SNLS477D October 2014 – February 2022 DS90UB948-Q1
PRODUCTION DATA
In normal operation, GPIO[3:0] may be used as GPIOs in either forward channel (outputs) or back channel (inputs) mode. GPIO and D_GPIO modes may be configured from the registers (Table 7-11). The same registers configure either GPIO or D_GPIO, depending on the status of PORT1_SEL and PORT0_SEL bits (0x34[1:0]). D_GPIO operation requires 2-lane FPD-Link III mode. Consult the appropriate serializer data sheet for details on D_GPIO configuration. Note: if paired with a DS90UB925Q-Q1 serializer, the devices must be configured into 18-bit mode to allow usage of GPIO pins on the serializer. To enable 18-bit mode, set serializer register 0x12[2] = 1. 18-bit mode is auto-loaded into the deserializer from the serializer. See Table 7-2 for GPIO 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 7-11).