Page History

Overview

A Lattice XO2-1200 CPLD (U19) is used as a System Management Controller. The SC is responsible for power sequencing, reset generation and zynq initial configuration (mode pin strapping). Moreover, some on-board ICs are connected to the SC that provides level shifting. The SC wakes up when the 3.3V input power rises above 2.1V (VIN voltage is not needed). The SC can turn on or off all of the other supplies on the module (except in no power sequencing mode when the 1.0V and 1.8 V supplies are forced to start immediately when power is applied to the module).

System Controller (SC)  was designed to allow ZYNQ PS system to access module special functions as early as possible without reducing the number of MIO pins that are fully user configurable.This early communication channel is done using MIO52 and MIO53 pins that are used also as ethernet PHY management interface for the on-board gigabit PHY. In order to simplify the boot process and reduce the number of time the PS peripherals need to be configured or re-initialized SC uses the same protocol on MIO52/MIO53 as the Gigabit PHY itself. This means that FSBL configures all peripherals to their final function, allocating MIO52 and MIO53 as ethernet MDIO interface. SC controller appears as "Virtual Ethernet PHY" on the MDIO bus of PS ethernet 0 interface. This interface is already available when Zynq PL Fabric is not configured. It would have been possible to use I2C protocol on MIO52/MIO53 but in such case some multiplexing would be needed to choose between two protocols, also it would be needed to change the peripheral mapping after first init by the FSBL. For use cases where ethernet PHY on TE0720 is not used at all, it is still possible to configure SC with design that implements I2C protocol on MIO52/MIO53 pins.For most use cases the only need to use this interface is access to MAC address info, this is normally done by u-boot loader that fetches the MAC address bytes and sets its environment variables accordingly. Linux image will then also be started so that the MAC address from EEPROM is used for ethernet 0 physical interface.

Feature Summary

• Power Management

• Reset Management

• JTAG Routing

• Boot Mode

• User IO

• LED

• MDIO Interface
• UNI/O MAC access
• Watchdog Timer
• I2C

Firmware Revision and supported PCB Revision

See Document Change History

Product Specification

Port Description

Functional Description

To access and control the following functions it must be accessed CR registers. For more information about how to access these registers refer to 111447303

JTAG

JTAG signals routed directly through the CPLD to FPGA. Access between CPLD and FPGA can be multiplexed via JTAGENB pin of CPLD (B9) (logical one for CPLD, logical zero for FPGA). This pin is connected to B2B (JM1-pin 89) directly. On the carrier board can be this pin enabled or disabled with a dip switch.

Boot Mode

TE0720 supports QSPI and SD card boot modes. Boot mode depends on the logic state of MODE pin of CPLD. This pin is directly connected to B2B connector. 

Watchdog Timer

Watchdog timer is an added option in the CPLD code. To control and to use watchdog timer correctly , it must be written correct values in the related CR registers.

For example to access these registers in FSBL code it can be used the following instruction:

• Status = XEmacPs_PhyWrite(&Emac, 0x1A, 7, 0xA500); if(Status != XST_SUCCESS){ return XST_FAILURE; } →  To enable WDT

• Status = XEmacPs_PhyWrite(&Emac, 0x1A, 7, 0x0000); if(Status != XST_SUCCESS){ return XST_FAILURE; } →  To disable WDT

• Status = XEmacPs_PhyWrite(&Emac, 0x1A, 12, 0x001F); if(Status != XST_SUCCESS){ return XST_FAILURE; } → To adjust desired time for WDT  

Another way to access the related registers for WDT is to use phytool command. It must be added the ethtool package in Linux. To add this package it must be chosen in petalinux configuration for rootfs this option. The path in petalinux rootfs is: Filesystem packages/console/network/ethtool

The phytool instruntion format is :

• Phytool read device/addr/register

• Phytool write device/addr/register <value>

To write desired value in the related WDT registers for example can be written the following instructions in Linux console:

• phytool write eth0/0x1A/7 0xA500 → WDT enable

• phytool write eth0/0x1A/7 0x0000 → WDT disable

• phytool write eth0/0x1A/12 0x001F → Adjusted WDT time. It depends on the period of the CPLD clock.

• phytool write eth0/0x1A/5 0x4000 → To set the WDT input clock high

• phytool write eth0/0x1A/5 0x0000 → To set the WDT input clock low

If the WDT is activated and the generated clock is fed to WDT input clock , it will not be reset the board (WDT_RST signal low). But if the generation of this clock is stopped , the board will be reset (WDT_RST signal high) after a period of time depending on the WDT_time (CR4[7:0] register value).
To test Watchdog timer can be fed a clock signal to WDT clock input. The following shell script file generates a clock for WDT input clock. This file must be copied as init.sh to the SD card additionally. This shell script file will be executed by booting the board and generates the WDT input clock automatically. As long as 1 key and enter key is not pressed, the WDT clock will be generated and subdequently the board will not be reset.  But if genetation of clock signal be stopped, the boad will be reset after a period of time. Note that WDT must already be activated in FSBL code.    

#WDT test
#!/bin/sh
echo "Starting the WDT Clock"
sleep 1
while :
do
    phytool read eth0/0x1A/5
    phytool write eth0/0x1A/5 0x4041
    sleep 0.5
    phytool read eth0/0x1A/5
    phytool write eth0/0x1A/5 0x0041
    sleep 0.5
	read -r -t 0.1 b
	echo "Press 1 to exit!"
    if (( b == 1 )) ; then
      break
    fi
done
printf "\Quit.......................\n\n"

Reset

Zynq will be reset, when it occures one of the following conditions:

Extra Reset

The board can also be reset through software.

For example the following instructions can reset the board:

• phytool write eth0/0x1A/7 0xE500 → Extra reset enable

• phytool write eth0/0x1A/5 0x8000 → Reset the board

It can be activated this option in FSBL code too:

• Status = XEmacPs_PhyWrite(&Emac, 0x1A, 7, 0xE500); if(Status != XST_SUCCESS){ return XST_FAILURE; }

Serial EEPROM

The seial EEPROM (U17) is used to save  MAC addess.  The MAC_IO pin of EEPROM uses UNI/O interface to communicate with CPLD. The connection between EEPROM chip and CPLD depends on the value of XIO4.

CryptoAuthentication

The CryptoAuthentication chip (U10) is a high-security hardware authentication device that allows use in many application same as checking user password. This device can communicate with 1MHZ I2C interface,single-wire interface or UART.

UART

I2C to GPIO block

This subsystem provides 32-bit (4 x 8-bit) of general purpose parallel input and output (I/O) expansion for the I2C bus protocol.  This module contain of  four 8-bit registers that the GPIO data can be saved in this registers with addresses from 0x20 to 0x23. It can be accessed this register with I2C commands in linux console or with i2c functions in FSBl code. To access the registers of the subsystem can be used the following commands in linux console:

• To see the i2c bus addresses :                                     i2cdetect -y -r 1    

• To read first register with address 0x20 :                         i2cget -y 1 0x20     

• To write for example 0x55 in first register with address 0x20 :    i2cset -y 1 0x20 0x55
  
  

The MIO7 pin is connected to third bit of GPIO input of the I2C to GPIO subsystem (register address 0x20).To test the I2C to GPIO subsystem the MIO7 state  can be changed  and the value of the first register (register address 0x20) can be monitored. The initial value of this register depends on the CPLD firmware and can be variable. In the following example the initial value of this register is equal to 0x30. That means that initial value of MIO7 is zero. Now set MIO7 to one and read the value of the first register with address 0x20 again. It should be equal to 0x34.

• To read the first register of the subsystem:

  • i2cget -y 1 0x20                               → For example here is equal to 0x30.

• To set MIO7 to one: 

  • cd /sys/class/gpio/

  • echo 913 > export

  • echo out > gpio913/direction

  • echo 1 > gpio913/value

• To read the first register of the subsystem again:

  • i2cget -y 1 0x20                               → It should be equal to 0x34.
    
    

The subsystem I2C to GPIO port mapping is according the following table:

GPIO input bit mapping:

UNI/O MAC read block

UNI/O bus is a low speed serial interface for embedded systems that requires only one logic signal SCIO (Serial Clock, Data Input/Output). By using Manchester encoding techniques, the clock and data are combined into a single, serial bit stream (SCIO),where the clock signal is extracted by the receiver to correctly decode the timing and value of each bit. The serial EEPROM (U17) interface is UNI/O. The UNI/O bus uses a master/slave configuration. In this system the serial EEPROM chip is slave and a UNI/O subsystem in CPLD works as master. Both master and slave can operate as transmitter or receiver, but the master device determines which mode is active.The UNI/O MAC read block in CPLD reads the MAC address from serial EEPROM chip during power-on.

Multiplexing uio data output between uio-id and uio-io:

SC Pins to B2B

SC Pins to FPGA

NOSEQ Pin

This is a dedicated input that forces the module's 1.0V and 1.8V supplies to be enabled if high. This pin has a weak pull-down on the module. If left open the module will power up in normal power sequencing enabled mode. This pin is 3.3V tolerant. This pin is also connected to the System Management Controller. The SC can read the status of this pin (it can be detected if the module is in power sequencing enabled mode). The SC can also use this pin as output after normal power on sequence.

No Sequencing mode

If the module is powered from a single 3.3V supply and power sequencing is disabled, then NOSEQ pin should be powered from the main 3.3V input. That is VIN, 3.3Vin and NOSEQ should all be tied together to the input 3.3V power rail. Sequencing mode should not be used if VIN is not 3.3V.

Normal mode

For normal operation leave NOSEQ open or pull down with a resistor.

Normal mode with user function on NOSEQ

NOSEQ can be used as an output after boot. NOSEQ must be low when 3.3V power is applied to the module. Common usage is an LED connected between NOSEQ and GND. The mapping of NOSEQ pin can be changed by CR1 register. The CR1 register is control register of MDIO slave interface that its content can be changed with  FSBL code, uboot command or in linux console directly.

SC MDIO Interface

Most registers and functions are available via ETH PHY Management interface (MIO pins 52 and 53).

Address

Register Overview

Register CR1

Register CR2

Register CR3

Register CR4

Register SR1

Register Details

Register CR1

The mapping of LED1(Green) , LED2(Red) and NOSEQ pin depends on the value of CR1 register.

Register CR2

The mapping of CPLD IOs (XIO4,XIO5,XIO6 and XCLK) that are connected directly with FPGA, can be changed using CR2 register.  

Register CR3

Register CR4

Note that the time of WDT depends on WTD_time register and the CPLD internal oscillator clock frequency. Default value for CR4 is 0x0000.

Register SR1

On-board LEDs

There are 3 on-board LEDs, with two of them connected to the System Management Controller and one to the Zynq PL (Done pin).

LED Status Codes

LED1 Green

This LED is mapped to MIO7 after power up. After the Zynq PS has booted it can change the mapping of this LED. If SC can not enable power to the Zynq then this LED will remain under SC control. It is available to the user only after the power supplies have stabilized and the POR reset to the Zynq is released. If watch dog timer is activated this LED will be assigned to the 7th bit of the counter of watch dog timer.

LED2 Red

This LED is used to show various signal or port states. The function of this LED can be changed by CR1 register.

LED3 Green (FPGA Done)

This green LED is connected to the FPGA Done pin which has an active low state. As soon as the Zynq is powered and the 3.3V I/O voltage is enabled, this LED will illuminate. This indicates that the Zynq PL is not configured. Once the Zynq PL has been configured the LED will go off.

During normal operation when the Zynq PL has been configured, the LED can be controlled from the FPGA fabric. Control of the LED in a user design requires the use of Xilinx startup primitive rather than a normal I/O primitive. If the startup primitive is not used then the LED will go off after configuration and remain off irrespectively of the user design.

This LED can not be controlled by the SC. If green LED3 does not light up at least for short time at power then there is major problem with power supplies, FPGA core and aux voltages may be missing.

CR registers access methods

System Controller can be accessed as PHY with address 0x1A on the ETH0 Management bus (MIO pins 52, 53). PHY at address 0x00 is the ETH0 onboard ethernet PHY Marvell 88E1512. PHY at address 0x1A is the System Controller. OUI 0x7201 should be decoded as Model TE0720-01. Model 0x01 is Assembly option. Rev 0x00 is the firmware major revision for the System Controller (Rev 0 is the initial version). The CR registers have individual number to be accessed in FSBL code or Linux console. These numbers are defined in mdio_slave_interface subsystem in CPLD VHDL code. Refer to 111447303 to see the table of CR registers.

The CR registers can be accessed in three methods. It can be used u-boot functions , FSBL code or phytool command in linux console to access these registers.

FSBL code

It is possible to access the CR registers in FSBL code. The following functions are used to write or read these resgisters.

• LONG XEmacPs_PhyWrite(XEmacPs *InstancePtr, u32 PhyAddress, u32 RegisterNum, u16 PhyData) → To write in CR registers

• LONG XEmacPs_PhyRead(XEmacPs *InstancePtr, u32 PhyAddress, u32 RegisterNum, u16 *PhyDataPtr) → To read CR registers

Note that to access this registers in FSBL code it must be written the following instruction before above commands: 

• Mac_Config = XEmacPs_LookupConfig(XPAR_PS7_ETHERNET_0_DEVICE_ID); if(Mac_Config == NULL) { return XST_FAILURE; }

• Status = XEmacPs_CfgInitialize(&Emac, Mac_Config, Mac_Config->BaseAddress); if(Status != XST_SUCCESS){ return XST_FAILURE; }

For example to write 0x0077 in CR1 register the following instruction is used: 

• XEmacPs_PhyWrite(&Emac, 0x1A, 5, 0x0077);

Note that the CR register names are CR1, CR2 , CR3 and CR4. But these registers are named in FSBL code register5, register6, register7 and register12 subsequently.

U-boot

Communication between Zynq and CPLD chip in mdio bus can be established anytime when ETH0 and management interface are enabled also before FPGA PL Fabric is configured too. 
System Controller Firmware version and some other version info can be read with u-boot command mii info:

• zynq-uboot> mii info

• PHY 0x00: OUI = 0x5043, Model = 0x1D, Rev = 0x01, 100baseT, FDX

• PHY 0x1A: OUI = 0x7201, Model = 0x01, Rev = 0x00, 10baseT, HDX

• zynq-uboot>

To write a value into CR registers or to read one of them the following instructions can be used:

• mii read <addr> <reg>

• mii write <addr> <reg> <data>

For example to read CR4 register the following instruction can be written in U-Boot command console:

• zynq-uboot> mii read 0x1A 0x0C

For example to write 0x0077 in CR1 can be written:

• zynq-uboot> mii write 0x1A 5 0x0077

LED1 and LED2 will be switched on.

Bit Decoding

Linux

It is possible to write into CR registers and to read these registers  in Linux console directly. To access the CR registers it must be added ethtool package , while linux image file is generated. To activate this option in petalinux this package must be chosen in configuration of rootfs in petalinux. The path for this package is:   Filesystem packages/console/network/ethtool
If this package is installed , phytool command can be used to access the CR registers. Phytool command format is: 

• phytool read device/addr/register

• phytool write device/addr/register <value>

For example to switch on LED1 and LED2 it must be written 0x0077 value in the register CR1:

• phytool eth0/0x1A/5 0x0077

To switch off these LEDs execute this instruction: 

• phytool eth0/0x1A/5 0x0066

Reading MAC address

It can be read MAC-address automatically. Customized u-boot reads MAC address and stores it in environment variables as required. Setting up MAC Address for Linux involves dynamic rewrite of FDT, this is done with u-boot script that starts Linux.
To read MAC address automatically, the following steps must be implemented:

In the FSBL code it must be written the following code additionally. This c file can be found in the following path: \test_board\sw_lib\sw_apps\zynq_fsbl\src\te_fsbl_hooks_te0720.c
For more information refer to TE0720 test board

u32 TE_FsblHookBeforeHandoff_Custom(void)
{
...
Mac_Config = XEmacPs_LookupConfig(XPAR_PS7_ETHERNET_0_DEVICE_ID); if(Mac_Config == NULL) { return XST_FAILURE; }
Status = XEmacPs_CfgInitialize(&Emac, Mac_Config, Mac_Config->BaseAddress); if(Status != XST_SUCCESS){ return XST_FAILURE; }
/*
* Read out MAC Address bytes
*/
Status = XEmacPs_PhyRead(&Emac, 0x1A, 9, &rval16); if(Status != XST_SUCCESS){ return XST_FAILURE; }
mac_addr[0] = (unsigned char)(rval16 >> 8); 
mac_addr[1] = (unsigned char)(rval16 & 0xFF);
Status = XEmacPs_PhyRead(&Emac, 0x1A, 10, &rval16); if(Status != XST_SUCCESS){ return XST_FAILURE; }
mac_addr[2] = (unsigned char)(rval16 >> 8); 
mac_addr[3] = (unsigned char)(rval16 & 0xFF);
Status = XEmacPs_PhyRead(&Emac, 0x1A, 11, &rval16); if(Status != XST_SUCCESS){ return XST_FAILURE; }
mac_addr[4] = (unsigned char)(rval16 >> 8); 
mac_addr[5] = (unsigned char)(rval16 & 0xFF);
...

/*
* Write MAC Address to OCM memory for u-boot to import!
*
*/

//strcpy(0xFFFFFC04, "ethaddr=00:0a:35:00:00:05\n" );
#ifdef UBOOT_ENV_MAGIC
Xil_Out32(UBOOT_ENV_MAGIC_ADDR, UBOOT_ENV_MAGIC); // Magic!
MacToUbootEnvironment((char*)UBOOT_ENV_ADDR, mac_addr);

/*
* Set MAC Address in PS7 IP Core registers
*/
Status = XEmacPs_SetMacAddress(&Emac, mac_addr, 1); if(Status != XST_SUCCESS){ return XST_FAILURE; }
...
}

Add the following definition in petalinux-configuration platform-top header file:

#define CONFIG_PREBOOT    "echo U-BOOT for petalinux;echo importing env from FSBL shared area at 0xFFFFFC00; if itest *0xFFFFFC00 == 0xCAFEBABE; then echo Found valid magic; env import -t 0xFFFFFC04; fi;setenv preboot; echo; dhcp"

• The platform-top.h file can be found in the following path: \petalinux\project-spec\meta-user\recipes-bsp\u-boot\files

• The Zynq SoC reads the MAC address from EEPROM by CPLD during power-on and copies this data in OCM (On-chip Memory). After that either in Linux or Uboot console MAC address can be accessed.

Appx. A: Change History and Legal Notices

Revision Changes

• changes REV05 to REV06

  • Generic options: PUDC and Boot Mode

  • MIO7 Pullnone

  • Adding internal en_3v3_int

  • JTAG C_* high impedance until 3.3VOUT can be high

  • Boot mode pins are GND or high impedance until en_3v3_int are high

  • MIO14,15 high impedance until en_3v3_int are high

  • JTAG time constraint correction

  • JTAG drive line adjustment

  • Bugfix I2C to GPIO module (I2C_to_GPIO.v)

  • Changed Firmware Identifier to REV06

• changes REV04 to REV05:

  •  0.05 watchdog

• changes REV03 to REV04:

  • NA

• changes REV02 to REV03:

  • NA

• changes REV01 to REV02:

  • added deglicht for EN1 and RESIN inputs

  • added VCORE ON when 3.3 OK signalled

Document Change History

To get content of older revision  got to "Change History"  of this page and select older document revision number.

Legal Notices