Expansion Bus Inbound State Diagram - Intel IXP45X Developer's Manual

Expansion Bus Controller—Intel
Processors
Figure 148. Expansion Bus Inbound State Diagram
EX_IXPCS_N = '1'
All States
EX_IXPCS_N = '0'
and
EX_WR_N = '1' and
EX_RD_N = '1'
Table 224. EX_ADDR Operation
Command EX_BURST
1-WORD WRITE
8-WORD WRITE
8-WORD WRITE
8-WORD WRITE
8-WORD WRITE
8-WORD WRITE
8-WORD WRITE
8-WORD WRITE
8-WORD WRITE
1-WORD READ
8-WORD READ
8-WORD READ
August 2006
Order Number: 306262-004US
® ®
IXP45X and Intel
EX_IXPCS_N = '0' and
(EX_WR_N = '0' or EX_RD_N = '0') and
not WAIT
IDLE
NOP
EX_IXPCS_N = '0' and
(EX_WR_N = '0' or EX_RD_N = '0') and
WAIT
WAIT <= (EX_WR_N = '0' and QueueFull) or
(EX_RD_N = '0' and (EX_BURST = '0' or
EX_ADDR[4:2] = "000"))
EX_ADDR[4:2
]
Assert EX_WAIT_N if QueueFull = '1'. Set QueueFull. Transfer Word to
0 X
AHB. Clear QueueFull when word is transferred.
1 0x0 Assert EX_WAIT_N if QueueFull = '1'. Write word 0 to data fifo.
1 0x1 Write word 1 to data fifo.
1 0x2 Write word 2 to data fifo.
1 0x3 Write word 3 to data fifo.
1 0x4 Write word 4 to data fifo.
1 0x5 Write word 5 to data fifo.
1 0x6 Write word 6 to data fifo.
Write word 7 to data fifo. Set QueueFull. Transfer all 8-words to AHB.
1 0x7
Clear QueueFull when all 8-words are transferred.
Assert EX_WAIT_N. Request 1-word from AHB. Deassert EX_WAIT_N
0 X
when data is retrieved from AHB and driven on EX_DATA.
Assert EX_WAIT_N. Request 8-words from AHB. Deassert EX_WAIT_N
1 0x0
when all 8-words are retrieved from AHB. Drive EX_DATA with word 0.
1 NOT (0x0) Drive EX_DATA with word EX_ADDR[4:2]
IXP46X Product Line of Network
Operation
® ®
Intel IXP45X and Intel IXP46X Product Line of Network Processors
DATA
(EX_WR_N = '0' and not QueueFull) or
(EX_RD_N = '0' and ReadDataReady)
WAIT
Developer's Manual
B4436-01
685