AC Electrical Characteristics
Electrical Characteristics
19-11
19.3.8
DRAM Hidden Refresh Cycle (Normal Mode)
Figure 19-8 on page 19-12 shows the DRAM hidden refresh cycle timing diagram for normal mode. The
signal values and units of measure for this figure are found in Table 19-10 on page 19-12. Detailed
information about the operation of individual signals can be found in Chapter 7, “DRAM Controller.”
Table 19-9. DRAM Write Cycle 16-Bit Access (CPU Bus Master) Timing Parameters
Number
Characteristic
(3.0 ± 0.3) V
Unit
Minimum
Maximum
1
Row address valid to RASx asserted
40
—
ns
2
DWE
asserted before CASx asserted
25
—
ns
3
OE
negated before RASx
asserted
0
—
ns
4
RASx asserted before row address invalid
(MSW = 0,1)
12,27
—
ns
5
Column address valid to CASx asserted
(MSW = 0,1)
10,25
—
ns
6
RASx asserted to CASx asserted (MSW = 0,1)
28,58
—
ns
7
RASx pulse width (SLW = 0,1)
90,120
—
ns
8
CASx
pulse width (BC[1:0] = 00,01,10,11)
28,58,88,118
—
ns
9
Data-out valid before CASx asserted
25
—
ns
10
Data-out hold after CASx
negated
25
—
ns
11
DWE negated after CASx
negated
0
—
ns
12
CASx asserted before column address invalid
50
—
ns
13
RASx negated after CASx negated
28
—
ns
14
RASx precharge time (SLW = 0,1)
50,118
—
ns
Note:
RASx stands for RAS0 and RAS1. CASx stands for CAS0 and CAS1.
Note:
MSW is bit 5, SLW is bit 3, and BC[1:0] comprises bits 13–12 in the DRAMC register. When the table
identifies these bits, the sequence of their listed values corresponds to the sequence of timing data provided.
Summary of Contents for MC68VZ328
Page 1: ...MC68VZ328UM D Rev 0 02 2000 MC68VZ328 Integrated Processor User s Manual ...
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Page 42: ...1 12 MC68VZ328 User s Manual Modules of the MC68VZ328 ...
Page 54: ...2 12 MC68VZ328 User s Manual In Circuit Emulation ICE Signals ...
Page 68: ...3 14 MC68VZ328 User s Manual Programmer s Memory Map ...
Page 110: ...6 22 MC68VZ328 User s Manual Programming Model ...