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PCI Bus
Data Bit-31
B7 B6 B5 B4 B3 B2 B1 B0
Transmit Data Byte n+3
Transmit Data Byte n+2
Transmit Data Byte n+1
Transmit Data Byte n+0
PCI Bus
Data Bit-0
Channel 0 to 7 Transmit Data in 32-bit alignment through the Configuration Register Address
0x0100, 0x0500, 0x0900, 0x0D00, 0x1100, 0x1500, 0x1900 and 0x1D00
XR17V358
33
REV. 1.0.4
HIGH PERFORMANCE OCTAL PCI EXPRESS UART
2.2
FIFO DATA LOADING AND UNLOADING THROUGH THE UART CHANNEL REGISTERS, THR
AND RHR IN 8-BIT FORMAT
The THR and RHR register address for channel 0 to channel 7 is shown in Table 10 below. The THR and RHR
for each channel 0 to 7 are located sequentially at address 0x0000, 0x0200, 0x0400, 0x0600, 0x0800,
0x0A000, 0x0C00 and 0x0E00. Transmit data byte is loaded to the THR when writing to that address and
receive data is unloaded from the RHR register when reading that address. Both THR and RHR registers are
16C550 compatible in 8-bit format, so each bus operation can only write or read in bytes.
TABLE 10: TRANSMIT AND RECEIVE DATA REGISTER IN BYTE FORMAT, 16C550 COMPATIBLE
THR and RH R Address Locations For C H0 to CH7 (16C550 Com patible)
C H0 0x0000 W rite THR
C H0 0x0000 Read RH R
C H1 0x0400 W rite THR
C H1 0x0400 Read RH R
C H2 0x0800 W rite THR
C H2 0x0800 Read RH R
C H3 0x0C00 W rite TH R
CH3 0x0C 00 R ead R HR
C H4 0x1000 W rite THR
C H4 0x1000 Read RH R
CH5 0x1400 W rite THR
CH5 0x1400 Read RH R
CH6 0x1800 W rite THR
CH6 0x1800 Read RH R
CH7 0x1C00 W rite TH R
C H7 0x1C00 R ead RH R
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0
Bit-7
Bit-6
Bit-5
Bit-4
Bit-3
Bit-2
Bit-1
Bit-0