TS-4100 FPGA

The TS-4100 FPGA registers are accessed over I2C. The /sys/class/gpio driver provides access to the IO using these registers. See the #GPIO section for more information on the recommended method for IO access.

The FPGA is available at I2C addresses 0x28-0x2f. First write the address which is 16-bits, followed by the data which is 8-bits.

The first registers 0-127 are used to control the GPIO. Use the IO offsets below from 0 to set the pin state.

GPIO Register Description

Bits	Description
7:3	Reserved (Write 0)
2	Input Data
1	Output Data
0	Output Enable

Registers 128-255 control the crossbar for the various pins. Use address 128 + IO number for the offset.

Crossbar Register Description

Bits	Description
7	GPIO mode (overrides crossbar)
6:0	Crossbar Value

The two registers above use this table for the offset. The crossbar support shows whether it can be mapped with the crossbar register above. The direction column describes if the IO is direction locked, or GPIO if they can be either. The directions are from the perspective of the FPGA, so for example UART TX from the CPU will be an input to the FPGA. The input data from that UART can be mapped to other pins offboard to pass through the data anywhere.

FPGA IO

IO Number	Pad	Crossbar support	Direction
1	UART3_TXD (ttymxc2)	Y	Input
2	UART3_RXD (ttymxc2)	Y	Output
3	UART3_RTSn (ttymxc2)	Y	Input
4	UART3_CTSn (ttymxc2)	Y	Output
5	UART4_TXD (ttymxc3)	Y	Input
6	UART4_RXD (ttymxc3)	Y	Output
7	UART7_TXD (ttymxc6)	Y	Input
8	UART7_RXD (ttymxc6)	Y	Output
9	SPARE_1 (UART1_CTS_B)	Y	GPIO
10	SPARE_2 (UART1_RTS_B)	Y	GPIO
11	WIFI_RESET	N	Output
12	EN_WIFI_PWR	N	Output
13	WIFI_TXD	Y	Output
14	WIFI_RXD	Y	Output
15	WIFI_RTS	Y	Input
16	WIFI_CTS	Y	Output
17	UART_A_TXD	Y	Output
18	UART_A_RXD	Y	Input
19	UART_B_TXD	Y	Output
20	UART_B_RXD	Y	Input
21	UART_C_TXD	Y	Output
22	UART_C_RXD	Y	Input
23	UART_D_TXD	Y	Output
24	UART_D_RXD	Y	Input
25	EN_HOST_USB_5V	N	Output
26	EN_LCD_3.3V	N	Output
27	EN_SD_POWER	N	Output
28	OFF_BD_RESET	N	Output
29	EN_SW_3.3V	N	Output
30	GREEN_LED	N	Output
31	RED_LED	N	Output