8xC251TA/TB/TP/TQ HIGH-PERFORMANCE CHMOS MICROCONTROLLER
6.3.2 External Bus Cycles, Page Mode
XTAL1
ALE
RD#/PSEN#
P2
P0/A16/A17
TOSC
TLHLL†
TLLRL†
†††
TRLDV†
TRLAZ
TLHAX†
TAVLL† TLLAX
TRHDZ1
TRHDX
A15:8
TAVRL†
TAVDV1†
TAVDV2†
A7:0/A16/A17
Page Miss††
D7:0
Instruction In
D7:0
Instruction In
TAVDV3
A7:0/A16/A17
Page Hit††
† The value of this parameter depends on wait states. See the table of AC characteristics.
†† A page hit (i.e., a code fetch to the same 256-byte "page" as the previous code fetch) requires one
state (2TOSC); a page miss requires two states (4TOSC).
††† During a sequence of page hits, PSEN# remains low until the end of the last page-hit cycle.
A4213-02
Figure 8. External Bus Cycle: Code Fetch (Page Mode)
ADVANCE INFORMATION
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