
52
Lattice Semiconductor
Data Sheet
September, 2002
ORCA Series 4 FPGAs
Microprocessor Interface (continued)
Table 25. Status Register Space Assignments
Notes: RO = Read Only. For internal system bus, bit 7 is most signicant bit, for MPI bit 0 is most signicant bit.
Table 26. Command Register Space Assignments
Note: R/W = Read/Write. For internal system bus; bit 7 is most signicant bit, for MPI bit 0 is most signicant bit.
Byte
bit
Read/Write
Description
0F
7:0
—
Reserved
0E
7:0
—
Reserved
OD
7
RO
Conguration Write Data Acknowledge
6RO
Readback Data Ready
5RO
Unassigned (Zero)
4RO
Unassigned (Zero)
3RO
FPSC_BIT_ERR
2RO
RAM_BIT_ERR
1RO
Conguration Write Data Size (1, 2, or 4 bytes)
0RO
Use with above for HSIZE[1:0] (byte, half-word, word)
0C
7
RO
Readback Addresses Out of Range
6RO
Error Response Received by CFG From System Bus
5RO
Error Responses Received by CFG From System Bus
4RO
CFG_DATA_LOST
3RO
DONE
2RO
INIT_N
1RO
ERR_FLAG 1
0RO
ERR_FLAG 0
Byte
bit
Read/Write
Description
0B
7:0
—
Reserved
0A
7:0
—
Reserved
09
7
R/W
SYS_GSR (GSR Input)
6
R/W
SYS_RD_CFG (similar to FPGA pin RD_CFGN, but active high)
5
R/W
PRGM from MPI > (similar to FPGA pin, but active high)
4
R/W
PRGM from USER > (similar to FPGA pin, but active high)
3
R/W
PRGM from FPSC > (similar to FPGA pin, but active high)
2
R/W
LOCK from MPI
1
R/W
LOCK from USER
0
R/W
LOCK from FPSC
08
7
R/W
Bus Reset from MPI (resets system bus and registers)
6
R/W
Bus Reset from USER (resets system bus and registers)
5
R/W
Bus Reset from FPSC (resets system bus and registers)
4
R/W
SYS_DAISY
3
R/W
REPEAT_RDBK (don't increment readback address)
2
R/W
MPI_USR_ENABLE
1
R/W
Readback Data Size (1, 2, or 4 bytes)
0
R/W
Use with above for HSIZE[1:0]