7 data retention during reset, Data retention during reset -10, Figure 7-3 – Motorola MC68VZ328 User Manual

Page 120: Data retention for the reset cycle -10

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7-10

MC68VZ328 User’s Manual

DRAM Controller Operation

7.2.7

Data Retention During Reset

DRAM needs to retain data during reset, whether it is an external reset or an internal watchdog reset. The
DRAM controller itself has a special design to support this feature. Figure 7-3 illustrates the timing for
data retention.

Figure 7-3. Data Retention for the Reset Cycle

32 kHz

DRAM Sync. with

System Clock

15.6 µs

Sleep with No SYSCLK

Reprogram
DRAM Controller,

External

RESET

(Hardware reset)

Internal

RESET

DRAM
Refresh

DRAM Reset
Port (CSCx, CSDx) Reset

System

Clock

Chip-Selects

I/O Port

(CSCx,CSDx),

CPCRESET

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