ZHCSJH7 March 2019 DS90UB940N-Q1
PRODUCTION DATA.
In normal operation, GPIOx pins may be used as GPIOs in either forward channel (outputs) or back channel (inputs) mode. GPIO and D_GPIO modes may be configured through the registers (Table 11). The same registers configure either GPIOx or D_GPIOx pins, depending on the status of PORT1_SEL and PORT0_SEL bits (0x34[1:0]). D_GPIO mode operation requires 2-lane FPD-Link III mode. Consult the appropriate serializer data sheet for details on D_GPIOx pin configuration.
NOTE
If paired with a DS90UB925Q-Q1 serializer, the devices must be configured for 18-bit mode to allow usage of GPIO pins on the serializer.
To enable 18-bit mode, set the serializer register 0x12[2] = 1. After setting the serializer register, 18-bit mode is auto-loaded into the deserializer from the serializer. See Table 2 for GPIOx pins enable and configuration.
DESCRIPTION | DEVICE | FORWARD CHANNEL | BACK CHANNEL |
---|---|---|---|
GPIO3 / D_GPIO3 | Serializer | 0x0F[3:0] = 0x3 | 0x0F[3:0] = 0x5 |
Deserializer | 0x1F[3:0] = 0x5 | 0x1F[3:0] = 0x3 | |
GPIO2 / D_GPIO2 | Serializer | 0x0E[7:4] = 0x3 | 0x0E[7:4] = 0x5 |
Deserializer | 0x1E[7:4] = 0x5 | 0x1E[7:4] = 0x3 | |
GPIO1 / D_GPIO1 | Serializer | 0x0E[3:0] = 0x3 | 0x0E[3:0] = 0x5 |
Deserializer | 0x1E[3:0] = 0x5 | 0x1E[3:0] = 0x3 | |
GPIO0 / D_GPIO0 | Serializer | 0x0D[3:0] = 0x3 | 0x0D[3:0] = 0x5 |
Deserializer | 0x1D[3:0] = 0x5 | 0x1D[3:0] = 0x3 |
The input value present on GPIO[3:0] or D_GPIO[3:0] may also be read from register or configured to local output mode (Table 11).
The GPIO0 pin also includes PASS and SDOUT functions. To allow GPIO0 control, PASS needs to be disabled by clearing bit 1 in indirect CSI register 0x16.
The GPIO3 pin can also be programmed to be the PASS pin. To allow GPIO3 control, PASS needs to be disabled by clearing bit 2 in indirect CSI register 0x16.