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Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors—Expansion Bus
Controller
Intel
®
IXP45X and Intel
®
IXP46X Product Line of Network Processors
Developer’s Manual
August 2006
694
Order Number: 306262-004US
decided to start another NOP cycle in cycle 3. If EX_WAIT_N was asserted in cycle 2,
the external master cannot start a NOP in cycle 3. It must wait until EX_WAIT_N is
sampled deasserted.
12.4.5.6
Eight-Word Inbound Write with EX_SLAVE_CS_N Deassertion
The above timing diagram shows an external master choosing to deassert
EX_SLAVE_CS_N in the middle of an 8-word write. The external master can deassert
EX_SLAVE_CS_N anytime after EX_WAIT_N is sampled deasserted. It can also deassert
it between any of the 8 words being transferred. In the above diagram, the master
deasserted EX_SLAVE_CS_N in cycle 3. When resuming the burst, the master must
increment EX_ADDR[4:2] by 0x1. Once the transfer for EX_ADDR[4:2] = 0x7 is
complete, the Expansion bus controller will transfer all 8 words to the AHB. The
Expansion bus controller will never assert EX_WAIT_N on word 2-8 of the burst.
Figure 155. Eight-Word Inbound Write with EX_SLAVE_CS_N Deassertion
B4443-01
EX_ CLK
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- 1 -
- 2 -
- 3 -
- 4 -
- 5 -
- 6 -
- 7 -
- 8 -
- 9 -
EX_ IXPCS_N
EX_ ADDR
EX_RD_N
EX_WR_N
EX_BE_N
EX_ BURST
EX_ WAIT_N
EX_ DATA
EX_ PARITY
STATE
- 10 -
ADDR0
IDLE
DATA1
ADDR2
DATA2
DATA2
PAR2
ADDR3
DATA3
DATA3
PAR3
ADDR4
DATA4
DATA4
PAR4
ADDR5
DATA5
DATA5
PAR5
ADDR6
DATA6
DATA6
PAR6
ADDR7
DATA7
DATA7
PAR7
IDLE
NOP
DATA0
DATA0
PAR0
ADDR1
DATA0
IDLE
DATA1
PAR1
- 11 -
- 12 -