APU0071-002WE-TY View Datasheet(PDF) - Anpec Electronics
Part Name
Description
MFG CO.
'APU0071-002WE-TY' PDF : 28 Pages View PDF
APU0071
RS
R/W
E
Internal
signal
DB7
DATA
Internal operation
Busy
Busy
No
Busy
DATA
Busy Flag Check
Busy Flag Check
INSTRUCTION
Busy Flag Check
INSTRUCTION
Fig 1. Example of 8-bit Bus Mode Timing Diagram
2-2. Interface with 4-bit MPU
When interfacing data lengths are 4-bit, only 4 ports, from DB4 to DB7, are used as data bus.
At first higher 4-bit (in case of 8-bit bus mode, the contents of DB4-DB7) are transferred, then the lower 4-
bit (in case of 8-bit bus mode, the contents of DB0-DB3) are transferred. So transfer is performed twice.
Busy Flag outputs “High” after the second transfer are ended.
Example of timing sequence is shown below.
RS
R/W
E
Internal
signal
DB7
D7 D3
Internal operation
Busy AC3
No
Busy AC3
D7 D3
INSTRUCTION
Busy Flag Check
Busy Flag Check
INSTRUCTION
Fig 2. Example of 4-bit Bus Mode Timing Diagram
Copyright ANPEC Electronics Corp.
16
Rev. A.07 - FEB., 2002
www.anpec.com.tw
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