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Figure 11-6. 16-bit write cycle – Rainbow Electronics DS31256 User Manual

Page 156

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DS31256

156 of 181

Figure 11-6. 16-Bit Write Cycle

Intel Mode (LIM = 0)
Arbitration Enabled (LARBE = 1)
Bus Transaction Time = 4 LCLK (LRDY = 0100)

An attempted access by the host causes the local bus to request the bus. If bus access has not been granted
(LBGACK deasserted), the timing shown at the top of the page applies, with LHOLD being asserted. Once
LHLDA is detected, the local bus grabs the bus for 32 to 1,048,576 clocks and then releases it. If the bus has
already been granted (LBGACK asserted), the timing shown at the bottom of the page applies.


















LCLK

LHOLD

LHLDA

LBGACK

32 to 1,048,576 LCLKs

LA[19:0]

LD[7:0]

LD[15:8]

LRD

LWR

Address Valid

LBHE

Data Valid

Data Valid

Three-State

Three-State

Three-State

Three-State

Three-State

Three-State

LCLK

1

2

3

4

Note: LA, LD,

LBHE, LWR, and LRD are three-stated.