80C251SB16 Datasheet, PDF (29/36 Pages) Intel Corporation – HIGH-PERFORMANCE CHMOS MICROCONTROLLER

8XC251SA/SB/SP/SQ HIGH-PERFORMANCE CHMOS MICROCONTROLLER
WCLK
ALE
WR#
WAIT#
P0
P2
State 1
State 2
State 3
State 4
T_WLYX max
T_WLYX min
T_WLYV
T_CLYV
T_CLYX min
T_CLYX max
WR# stretched
A0-A7
D0-D7
A8-A15
stretched
stretched
Figure 14. External Bus Cycle: Data Write (Nonpage Mode)
A5002-01
WCLK
ALE
RD#/PSEN#
WAIT#
State 1
State 2
State 3
State 1 (next cycle)
T_RLYX max
T_RLYX min
T_RLYV
T_CLYV
T_CLYX min
T_CLYX max
RD#/PSEN# stretched
P2
A8-A15
D0-D7
stretched
A8-A15
P0
A0-A7
stretched
A0-A7
Figure 15. External Bus Cycle: Code Fetch/Data Read (Page Mode)
A5001-01
PRELIMINARY
29