Rainbow Electronics W78C32C - Manual (Page 9)

W78C32C
Publication Release Date: July 1999
- 9 - Revision A2
Port Access Cycle
PARAMETER SYMBOL MIN. TYP. MAX. UNIT
Port Input Setup to ALE Low T PDS 1 T CP - - nS
Port Input Hold from ALE Low T PDH 0 - - nS
Port Output to ALE T PDA 1 T CP - - nS
Note: Ports are read during S5P2, and output data becomes available at the end of S6P2. The timing data are referenced to
ALE,
since it provides a convenient reference.
TIMING WAVEFORMS
Program Fetch Cycle
S1
XTAL1
S2 S3 S4 S5 S6 S1 S2 S3 S4 S5 S6
ALE
PORT 2
A0-A7 A0-A7 Data A0-A7 Code
T
A0-A7 Data Code
PORT 0
PSEN
PDH, T PDZ
T PDA T AAH
T AAS
T PSW
T APL
T ALW
Data Read Cycle
S2 S3 S5 S6 S1 S2 S3 S4 S5 S6 S1 S4
XTAL1
ALE
PSEN
DATA
A8-A15 PORT 2
PORT 0
A0-A7
RD
T DDH, T DDZ
T
DDA
T DRD
T DAR