XR17V358 Datasheet, PDF (32/68 Pages) Exar Corporation – HIGH PERFORMANCE OCTAL PCI EXPRESS UART

XR17V358
PRELIMINARY
HIGH PERFORMANCE OCTAL PCI EXPRESS UART
REV. P1.0.2
Channel 0 to 7 Receive Data in 32-bit alignment through the Configuration Register Address
0x0100, 0x0500, 0x0900, 0x0D00, 0x1100, 0x1500, 0x1900 and 0x1D00
Receive Data Byte n+3
Receive Data Byte n+2
Receive Data Byte n+1
Receive Data Byte n+0
B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0
PCI Bus
Data Bit-31
PCI Bus
Data Bit-0
2.1.2 Special Rx FIFO Data Unloading at locations 0x0200, 0x0600, 0x0A00, 0x0E00, 0x1200,
0x1600, 0x1A00, and 0x1E00
The XR17V358 also provides the same RX FIFO data along with the LSR status information of each byte side-
by-side, at locations 0x0200 (channel 0), 0x0200 (channel 1), 0x0A00 (channel 2), ....., 0x1E00 (channel 7).
The entire RX data along with the status can be downloaded in a single PCI Burst Read operation of 32
DWORD reads. The Status and Data bytes must be read in 16 or 32 bits format to maintain data integrity. The
following tables show this clearly.
READ RX FIFO,
WITH LSR ERRORS
Read n+0 to n+1
Read n+2 to n+3
Etc
BYTE 3
FIFO Data n+1
FIFO Data n+3
BYTE 2
LSR n+1
LSR n+3
BYTE 1
FIFO Data n+0
FIFO Data n+2
BYTE 0
LSR n+0
LSR n+2
Channel 0 to 7 Receive Data with Line Status Register in 32-bit alignment through the Configuration
Register Address 0x0200, 0x0600, 0x0A00, 0x0E00, 0x1200, 0x1600, 0x1A00 and 0x1E00
Receive Data Byte n+1
Line Status Register n+1
Receive Data Byte n+0
Line Status Register n+0
B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0 B7 B6 B5 B4 B3 B2 B1 B0
PCI Bus
Data Bit-31
PCI Bus
Data Bit-0
2.1.3 Tx FIFO Data Loading at locations 0x100, 0x500, 0x900, 0xD00, 0x1100, 0x1500, 0x1900, and
0x1D00
The TX FIFO data (up to the maximum 256 bytes) can be loaded in a single burst 32-bit write operation
(maximum 16 DWORD writes) at memory locations 0x0100 (channel 0), 0x0500 (channel 1), 0x0900 (channel
2), ............, 0x1900 (channel 6) and 0x1D00 (channel 7).
WRITE TX FIFO
Write n+0 to n+3
Write n+4 to n+7
Etc.
BYTE 3
FIFO Data n+3
FIFO Data n+7
BYTE 2
FIFO Data n+2
FIFO Data n+6
BYTE 1
FIFO Data n+1
FIFO Data n+5
BYTE 0
FIFO Data n+0
FIFO Data n+4
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