19-4 MC68VZ328 User’s Manual
AC Electrical Characteristics
Figure 19-2. Chip-Select Read Cycle Timing DiagramTable 19-4. Chip-Select Read Cycle Timing Parameters
Number Characteristic (3.0 ± 0.3)V Unit
Minimum Maximum
1 Address valid to CSx asserted
(bit ECDS= 0, bit ECDS =1) 20, 20 -T/2 —ns
2UWE/LWE negated before row address valid 0 ns
3CSx
asserted to OE asserted 0 ns
4 Data-in valid from CS x asserted 35 + nT ns
5 External DTACK input setup from CSx asserted 20 + nT ns
6CSx
pulse width
(bit ECDS= 0, bit ECDS =1) 60 + nT,
(60+ T/2) + nT —ns
7 External DTACK input hold after CSx is negated 0 ns
8 Data-in hold after CSx is negated 0 ns
9OE
negated after CSx is negated 0 10 ns
10 UB/LB asserted to CSx asserted (16-bit SRAM) 10 ns
A[31:0]
CSx
UWE/LWE
OE
D[15:0]
DTACK
UDS/LDS
UB/LB
1 6
2
3 9
4
5
8
7
1110