
33
4428E–8051–02/08
AT/TS80C31X2
14.5.2
External Program Memory Read Cycle
Figure 14-6. External Program Memory Read Cycle
Table 14-8.
External Data Memory Characteristics
T
PLIV
TPLAZ
ALE
PSEN
PORT 0
PORT 2
A0-A7
INSTR IN
ADDRESS
OR SFR-P2
ADDRESS A8-A15
12 TCLCL
T
AVIV
T
LHLL
T
AVLL
T
LLIV
T
LLPL
TPLPH
TPXAV
T
PXIX
T
PXIZ
T
LLAX
Symbol
Parameter
T
RLRH
RD Pulse Width
T
WLWH
WR Pulse Width
T
RLDV
RD to Valid Data In
T
RHDX
Data Hold After RD
T
RHDZ
Data Float After RD
T
LLDV
ALE to Valid Data In
T
AVDV
Address to Valid Data In
T
LLWL
ALE to WR or RD
T
AVWL
Address to WR or RD
T
QVWX
Data Valid to WR Transition
T
QVWH
Data set-up to WR High
T
WHQX
Data Hold After WR
T
RLAZ
RD Low to Address Float
T
WHLH
RD or WR High to ALE high