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Intel, Ixp2800 network processor intel xscale, Hardware reference manual 153 – Intel NETWORK PROCESSOR IXP2800 User Manual

Page 153

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Hardware Reference Manual

153

Intel

®

IXP2800 Network Processor

Intel XScale

®

Core

16-Bit Microprocessor Write Interface Protocol

Figure 43

uses the Lucent* TDAT042G5 device. In this case, the user should program the P_PCR

register to mode 1 and also program the write timing control register to setup=7, pulse width=5,
and hold=1, which represent seven clock cycles for CS, five clock cycles for DT delay, and one
clock cycle for ADS. They are intervened with two idle cycles.

From

Figure 43

, we observe that there are a total of twelve clock cycles used for write access,

(i.e., 240 ns), not including an intervened turnaround cycle after the write transaction. The

throughput is 8.3 Mbytes per second.

Figure 43. Mode 1 Single Write Transfer for Lucent* TDAT042G5 Device (B0)

B1742-04

SP_CLK

SP_ALE_L

SP_CS_L[1] /CS#

SP_WR_L/ADS#

SP_RD_L/R/W#

2

T0

T1

T2

T3 T4

T0

T1

T2

T3 T4

T5

T6

0

4

6

8

10

12

14

16

18

20

SP_AD[7:0]

SP_ACK_L /DT#

SP_CP

SP_OE_L

D[15:0]

A[23:0]

A[23:0]

SP_DIR

ADDR[15:0]

DATA[15:0]

A

[15:0]

A

[15:8]

A

[7:0]

A

[23:16]

A

[15:8]

A

[7:0]

A

[23:16]

D

[7:0]

D[15:8]

D

[7:0]

A

[15:0]

A

[7:0]

A

[7:0]