Rainbow Electronics AT75C310 - Manual (Page 61)

AT75C310
61
USART User Interface
Base Address USART A: 0xFF018000
Base Address USART B: 0xFF01C000
Notes: 1. This may be 0x18 or 0x418 depending on the value of bootn and modem control inputs.
2. This depends on the value of modem control input signals, as these are reflected in this register.
Offset Register Description Register Name Access Reset State
0x00 Control Register US_CR Write-only –
0x04 Mode Register US_MR Read/write 0
0x08 Interrupt Enable Register US_IER Write-only –
0x0C Interrupt Disable Register US_IDR Write-only –
0x10 Interrupt Mask Register US_IMR Read-only 0
0x14 Channel Status Register US_CSR Read-only 0x18 (1)
0x18 Receiver Holding Register US_RHR Read-only 0
0x1C Transmitter Holding Register US_THR Write-only –
0x20 Baud Rate Generator Register US_BRGR Read/write 0
0x24 Receiver Time-out Register US_RTOR Read/write 0
0x28 Transmitter Time-guard Register US_TTGR Read/write 0
0x2C Reserved – – –
0x30 Receive Pointer Register US_RPR Read/write 0
0x34 Receive Counter Register US_RCR Read/write 0
0x38 Transmit Pointer Register US_TPR Read/write 0
0x3C Transmit Counter Register US_TCR Read/write 0
0x40 Modem Control Register US_MC Write-only –
0x44 Modem Status Register US_MS Read-only (See Note 2)