Intel NETWORK PROCESSOR IXP2800 - Manual (Page 160)

160 Hardware Reference Manual
Intel
®
IXP2800 Network Processor
Intel XScale ® Core
Mode 3 Write Interface Protocol
Figure 50 depicts a single write transaction launched from the IXP2800 Network Processor to the
Intel and AMCC* SONET/SDH device, followed by two consecutive reads.
Compared with the Lucent* TDAT042G5, this device has a shorter access time, about eight clock
cycles (i.e., 160 ns). In this case, an intervening cycle may not be needed for the write transactions.
Therefore, the throughput is about 12.5 Mbytes per second.
Figure 50. Mode 3 Single Write Transfer Followed by Read (B0)
B1749-04
SP_CLK
SP_ALE_L
SP_CS_L[1]/CSB
SP_WR_L/WRB
SP_RD_L/RDB
2 0 4 6 8 10 12 14 16 18 20
SP_AD[7:0]
SP_ACK_L/INT
SP_CP
SP_OE_L
A[10:1] A[10:1]
SP_DIR
ADDR[15:0]
DATA[15:0]
A
[10:8]
A
[7:0]
A
[15:8]
A
[7:0]
A
[15:8] D[15:8] A
[7:0]
A
[7:0]
D
[7:0] D[15:8] D[7:0]
D[15:0] D
[15:8] D[15:0] 2xD[15:8] D[15:0]