DS90UB941AS-Q1: Pass-through problem in port1 D_GPIO2

Hi Loki,

If the PWM of Port 0 works and the PWM of Port 1 does not work, there may be differences in the GPIO setup causing the received signal to be incorrect. Can you confirm the following?

• Port 0 PWM Frequency
• Port 1 PWM Frequency
• Port 0 PCLK Frequency
• Port 1 PCLK Frequency

Attached is a script that shows the register configuration for the 941 and 948 GPIOs. Does this match your setup?

serAddr = 0x18
desAlias0 = 0x34
desAlias1 = 0x36

#941 - Port 0 GPIO
board.WriteI2C(serAddr, 0x1E, 0x1) #Port 0 SEL
board.WriteI2C(serAddr, 0xD, 0x3) #GPIO0 input

#941 - Port 1 GPIO
board.WriteI2C(serAddr, 0x1E, 0x2) #Port 1 SEL
board.WriteI2C(serAddr, 0xE, 0x30) #D_GPIO2 input

#948-A GPIO configuration
board.WriteI2C(desAlias0,0x1D, 0x5) #GPIO0 output, enable Remote GPIO control

#948-B GPIO configuration
board.WriteI2C(desAlias1,0x1E, 0x50) #GPIO2 output, enable Remote GPIO control

Best,

Jack

Dear Jack：

     My configuration is consistent with what you gave, and the pwm frequency on PORT0 and PORT1 is the same, both are 200HZ. We use 941 VCs spliter mode, and the soc dsi packs two signals (VC0 and VC1). The 941 side parses VC0 and VC1 signals to port0 and port1 respectively, and port0 and port1 have the same PCLK, and then connect two 948 channels respectively. Two 948s are connected to two identical screens. The block diagram is as follows:

Dear jack：

    The configuration for 948 is a bit different. When I configured 948-B, I set 0x34 to 0x2 and then set 0x1E to 0x50，and the rest is the same.

Hi Loki,

I'll get back with you shortly.

Best,

Jack

Dear jack：

    But I have learned that port1 of 941 can only use D_GPIO passthrough.And the actual experiment is also the same, port1 of 941 cannot pass through GPIO signal, only port0 can.

Dear jack:

    Configuring GPIO2 is now OK, thank you very much.