TE0630 is provided with a Dip switch S1B.
Dip switch S1B conditions the value of signal PS_EN.
In this way, S1B conditionally/unconditionally enables the power rails 1.2 V, 1.5 V and 2.5 V.

Please note the 4 switch labels are on one side and the <ON> label is on the opposite side.

DIP slide switches S1[A:D] condition the value of some system signals as described in the table below.

When S1B is turned off  (FX2 PON position), the 1.2 V, 1.5 V and 2.5 V power rails are controlled by the USB (EZ-USB FX2LP USB FX2) microcontroller. At start-up, the USB microcontroller switches off the power rails 1.2 V, 1.5 V and 2.5 V and starts up the module in low-power mode. After enumeration, the USB microcontroller firmware enables (switches on) the power rails 1.2 V, 1.5 V and 2.5 V, if enough current is available from the USB bus.

When S1B is turned on (PON position), the power rails 1.2 V, 1.5 V and 2.5 V are always enabled (switched on).

S1B position Default position Effect on 1.2 V, 1.5 V and 2.5 V rails FX2 PON (off)  Power rails 1.2 V, 1.5 V and 2.5 V controlled by USB FX2 microcontroller (signal FX2_PS_EN) PS_EN = FX2_PS_EN = 1 or 0 PON (on) Power rails 1.2 V, 1.5 V and 2.5 V always enabled (PS_EN = 1) PS_EN ≠ FX_PS_EN = 1 or 0

Signal FX2_PS_EN

To command signal FX2_PS_EN, read the reference firmware code.
IOD = 0x03; // Enable PS_EN and disable PROG_B
OED = 0x03; // Configure PS_EN and PROG as outputs

 

Table from EZ-USB(R) Technical Reference Manual (EZ-USB_TRM.pdf) Port D Pin Alternate Function Alternate Function is Selected By... Alternate Function is Described in... PD[7:0] FD[15:8] IFCFG1 = 1 and any WORDWIIDE bit = 1 Slave FIFOs chapter 9 on page 99

Signal PS_EN

• Signal PS_EN enables (1) or disables (0) power rails 1.2 V, 1.5 V and 2.5 V.

  
  

• Power-rail 3.3V is not controlled by signal PS_EN and is unconditionally enabled. 

   
  

VCCIO assembly options

According to the corresponding assembly option, power rail VCCCIO0 (enabled by PS_EN and switch S1B ) can depend or not on the power rail 2.5V.

VCCIO0 voltage can be configured in 3 ways:

• 2.5V - When resistor R103 is populated and resistor R102 is not populated.
• 3.3V - When R103 is not populated and resistor R102 is populated.
• 1.2 V ÷ 3.3 V (External supply) - When R103 is not populated and R102 is not populated. In this case external supply source have to be connected to pins 1, 2, 3, 4 of J4 B2B connector⁽¹⁾.

 ⁽¹⁾ See Spartan-6 documentation fo VCCIO power range.

 

 

Others options of VCCIO0 power supply are not supported and can damage the FPGA!

See the figure below to locate R102 and R103 on PCB.

Dip Switch S1B = FX2 PON 

When Dip switch S1B is in the left position ( = FX2 PON : power rails conditionally on depending on signal FX2_PS_EN), signal PS_EN is set to signal FX2_PS_EN (PS_EN = FX2_PS_EN) driven by the EZ-USB FX2LP USB FX2 microcontroller under user control (IOD and OED of fw.c).

1. Dynamic full power operation (PS_EN = 1): when the EZ-USB FX2LP USB FX2 microcontroller sets signal PS_EN = FX2_PS_EN = high, power rails 1.2 V, 1.5 V and 2.5 V are enabled.
   This setting can be useful for .
2. Dynamic low power operation (PS_EN = 0): when the EZ-USB FX2LP USB FX2 microcontroller resets signal PS_EN = FX2_PS_EN = low, the following components are switched off:

• • FPGA core logic (1.2 V)
  • DDR SDRAM (2.5 V)
  • FPGA bank 1 (1.5 V)
  • VREF1 (0.75 V)
  • VCCCIO0 (2.5 V) FPGA bank 0 (if R102+R103- assembly)

Dip Switch S1B = PON 

Summary table

The table below summarizes all switching options implied by Dip switch S1B and firmware signal FX2_PS_EN (under the standard assembly option).