DS90UB954-Q1: How to set GPIOs

Nao

Part Number: DS90UB954-Q1
Other Parts Discussed in Thread: ALP

Hi, E2E members

I have a DS90UB953 linked to a DS90UB954.
I would like to use 3 forward Channel GPIO and 1 Back Channel GPIO.
However, I can't find DATAPATH_CTL1: FC_GPIO_EN for 3 forward Channel GPIO settings.

How do I need to set for using 3 forward Channel GPIO and 1 Back Channel GPIO?

Regards,
Nao

over 7 years ago

0 Hamzeh Jaradat over 7 years ago

TI__Guru** 107360 points

Hello Nao,

There are 3 main controls for GPIO:
1. GPIO I/O setting & mapping on serializer
2. GPIO I/O setting & mapping on Deserializer
3. FPD forward channel GPIO control.

They are all required. What you configured on the FPD forward channel GPIO does not control the GPIO I/O or mapping setting. You need to set both.
So you still can set in the 953 reg 0x59[1:0] =11 (Four GPIOs) but configure the fourth one as Back-Channel GPIO, i.e. as input on the 954 and output on the 953.

0 Nao over 7 years ago in reply to Hamzeh Jaradat

Genius 4905 points

Hi, Hamzeh

Thank you for your reply.
Do you have some sample code for FC_GPIO setting on ALP?

Regards,
Nao

0 Hamzeh Jaradat over 7 years ago in reply to Nao

TI__Guru** 107360 points

Hello Nao,

To send a signal from Serializer to Deserializer via GPIO over the forward channel, you will need some or all of the following registers:

On the 953:

Reg 0x0E

Reg 0x0D

Reg 0x33

Reg 0x53

On the 954:

Reg 0x12

Reg 0x0F

Reg 0x59

For example sending a voltage level over GPIO2,

On the 953, write reg 0x0E[2]=1 and [6]=0

Reg 0x0D

Reg 0x33 = 0x07

On the 954, write reg 0x12=0x41

Reg 0x0F[2]=0

Reg 0x59[1:0]

0 Nao over 7 years ago in reply to Hamzeh Jaradat

Genius 4905 points

Hi, Hamzeh

Thank you for your quick reply.
I was able to use FC_GPIO on our EVM.

Regards,
Nao

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DS90UB954-Q1: How to set GPIOs