7733 Datasheet, PDF (740/940 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER

APPLICATIONS
17.1 Memory expansion
Ž When using an external memory which outputs data for more than an interval of tpzx(RDE-DZ)
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after signal RDE’s rising edge
When there is a possibility that the tail of data collides with the head of an address because the
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external memory outputs the data for more than an interval of tpzx(RDE-DZ) after signal RDE’s rising
edge, try to carry out the following:
q By using bus buffers and others, delete the tail of data which is output from the memory.
q Use a memory which is made by MITSUBISHI ELECTRIC CORPORATION and can be connected
without bus buffers.
Figures 17.1.8 to 17.1.11 show bus buffer usage examples and the corresponding timing diagrams.
Table 17.1.5 lists memories which can be connected without bus buffers (made by MITSUBISHI
ELECTRIC CORPORATION). The reason why these memories do not need buffers is that timing
parameters tDF or tdis(OE) is guaranteed. (Make sure that the read signal rises within 5 ns after signal
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RDE’s rising edge.)
Table 17.1.5 Memories which can be connected without bus buffers (made by MITSUBISHI ELECTRIC CORPORATION)
Memory
EPROM
Type
M5M27C256AK-85, -10, -12, -15
M5M27C512AK-10, -12, -15
M5M27C100K-12, -15
M5M27C101K-12, -15
tDF/tdis(OE) (Max.)
15 ns
(When guaranteed as kit)
(Note)
Usage condition
2 • f(f2) ≤ 20 MHz
M5M27C102K-12, -15
M5M27C201K, JK-10, -12, -15
M5M27C202K, JK-10, -12, -15
One time M5M27C256AP, FP, VP, RV-12, -15
PROM
M5M27C512AP, FP-15
M5M27C100P-15
M5M27C101P, FP, J, VP, RV-15
M5M27C102P, FP, J, VP, RV-15
M5M27C201P, FP, J, VP, RV-12, -15
M5M27C202P, FP, J, VP, RV-12, -15
Frash
M5M28F101P, FP, J, VP, RV-10, -12, -15
memory
M5M28F102FP, J, VP, RV-10, -12, -15
SRAM
M5M5256CP, FP, KP, VP, RV-55LL, -55XL,
-70LL, -70XL, -85LL, -85XL, -10LL, -10XL
M5M5278CP, FP, J-20, -20L
M5M5278CP, FP, J-25, -25L
8 ns
10 ns
2 • f(f2) ≤ 25 MHz
M5M5278DP, J-12
6 ns
M5M5278DP, FP, J-15, -15L
7 ns
M5M5278DP, FP, J-20, -20L
8 ns
Note: Specifications of the above memories are available if a comment “tDF/tdis = 15 ns, microcomputer and
kit” is added.
17–14
7735 Group User’s Manual