W39V040FB View Datasheet(PDF) - Winbond

Part Name

Description

Manufacturer

W39V040FB

512K × 8 CMOS FLASH MEMORY WITH FWH INTERFACE

Winbond 

W39V040FB

13. TIMING WAVEFORMS FOR FWH INTERFACE MODE

13.1 Read Cycle Timing Diagram

TCYC

CLK

#RESET

TSU THD

FWH4

FWH[3:0]

Start

FWH IDSEL

Read

1101b 0000b

TSU THD

Address

XXXXb XA[22]XXb A[18:16] A[15:12] A[11:8] A[7:4] A[3:0]

1 Clock 1 Clock

Load Address in 7

Clocks

TKQ

M Size

TAR

Sync

0000b 1111b Tri-State 0000b

Data

TAR

Next Start

D[3:0] D[7:4] 1111b Tri-State 0000b

2 Clocks

1 Clock Data out 2 Clocks

2 Clocks 1 Clock

Note: When A22 = high, the host will read the BIOS code from the FWH device.

While A22 = low, the host will read the GPI (Add = FFBC0100) or

Product ID (Add = FFBC0000/FFBC0001) from the FWH device

13.2 Write Cycle Timing Diagram

CLK

#RESET

FWH4

FWH[3:0]

TCYC

TSU THD

Start

FWH

Write

IDSEL

Address

1110b 0000b XXXXb XXXXb A[18:16] A[15:12] A[11:8] A[7:4]

A[3:0]

M Size

Data

0000b D[3:0] D[7:4]

TAR

Sync

1111b Tri-State 0000b

TAR

Next Start

1111b Tri-State 0000b

1 Clock1 Clock

Load Address in 7 Clocks

Load Data in 2 Clocks 2 Clocks 1 Clock

2 Clocks

1 Clock

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