TS-4800 UARTs
The TS-4800 CPU has 3 UARTS brought out. The XUARTs compliment this by adding 4 additional UARTS with one that can be remapped for RS422. Our XUART core will support up to 8 XUARTs total so contact us for FPGA customization options if you require more, or see the #FPGA Programming section.
All of these UARTs are brought out as 3.3V TTL, but various have level shifters and transceivers to use these at RS232/RS422/RS485. Refer to your baseboard manual or schematics for more information. The CPU UARTs will have device entries at /dev/ttymxc#. The XUARTs do not by default have a device entry. See the xuartctl page for details on using the XUARTs.
| Port | RX | TX | TX Enable | Notes |
|---|---|---|---|---|
| ttymxc0 | CN2_95 | CN2_93 | N/A | |
| XUART0 | CN2_78 | CN2_80 | CN1_67 (DIO_12) | Toggle with xuart0_on and xuart0_off. |
| ttymxc1 | CN2_84 | CN2_82 | N/A | |
| ttymxc2 | CN2_88 | CN2_86 | N/A | |
| XUART1 | CN2_92 | CN2_90 | N/A | Toggle with xuart3_on xuart3_off |
| XUART2 | CN2_96 | CN2_94 | CN1_63 (DIO_14) | Toggle with xuart4_on xuart4_off. |
| XUART3 | CN2_100 | CN2_98 | N/A | Toggle with xuart5_on xuart5_off |
| XUART0 | CN1_65 | N/A | N/A | This is RX only. Must be remapped by toggling syscon offset 0x16 bit 12. |
| Note: | The xuart#_on/off functions are not needed in REV 7 of the FPGA. See the #FPGA section for more details. |
To remap the XUART0 from CN2_78-CN2_80 to RX Only on CN1_65 you must set this bit in the syscon:
peekpoke 16 0xb0010016 0x1023