
APPLICATION
7702/7703 Group User’s Manual
17–15
17.1 Memory expansion
When using external memory that outputs data for more than tpzx(E-P1Z/P2Z) after rising edge of
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E signal
Because the external memory outputs data for more than tpzx(E-P1Z/P2Z) after the rising edge of the
_
E signal, there will be a possibility of the tail of data colliding with the head of address. In this case,
examine the method described below.
q Cut the tail of data output from the external memory by using a bus buffer and others.
q Use the Mitsubishi’s memories that can be connected without a bus buffer.
Figures 17.1.11 to 17.1.14 show examples for how to use a bus buffer and the timing diagrams.
Table 17.1.7 lists the memories that can be connected without a bus buffer. These memories do
not require a bus buffer because timing parameters tDF and tdis(OE) listed below are guaranteed.
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(However, the read signal must go high within 10 ns after the rising edge of E signal.)
Table 17.1.7 Memories that can be connected without bus buffer
Type description
M5M27C256AK-85, -10, -12, -15
M5M27C512AK-10, -12, -15
M5M27C100K-12. -15
M5M27C101K-12, -15
M5M27C102K-12, -15
M5M27C201K, JK-10, -12, -15
M5M27C202K, JK-10, -12, -15
M5M27C256AP, FP, VP, RV-12, -15
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
M5M28F101P, FP, J, VP, RV-10, -12, -15
M5M28F102FP, J, VP, RV-10, -12, -15
M5M5256CP, FP, KP, VP, RV-55LL, -55XL,
-70LL, -70XL, -85LL, -85XL, -10LL, -10XL
M5M5278CP, FP, J-20, -20L
M5M5278CP, FP, J-25, -25L
M5M5278DP, J-12
M5M5278DP, FP, J-15, -15L
M5M5278DP, FP, J-20, -20L
Memory
EPROM
One-time PROM
Frash memory
SRAM
Conditions
f(XIN)
≤ 20 MHz
f(XIN)
≤ 25 MHz
tDF/tdis(OE) (Maximum)
15 ns
(Guaranteed by kit) (Note)
8 ns
10 ns
6 ns
7 ns
8 ns
Note: When the user needs a specification of the memories listed above, add the comment “tDF/tdis(OE) 15 ns
product, microcomputer and kit.”