14 external memory space access (dram space), 1 dram space – Panasonic MN103001G/F01K User Manual

Page 176

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Bus Controller (BC)

8-62

8.14 External Memory Space Access (DRAM Space)

8.14.1

DRAM Space

Blocks 1 and 2 can be used as DRAM space by setting the BnDRAM bits in memory control registers 1B/2B and

setting the DRAME bit in DRAM control register. The DRAM bus cycle is always not synchronized the external
clock (but is synchronized with MCLK), and performs address multiplexed output, RAS/CAS signal output, etc.

Note: When common pins are used for addresses and data, DRAM cannot be supported.

The RAS/CAS signal output timing can be set through software in the DRAM control register and memory control

registers 1A/B and 2A/B.
Fig. 8-14-1 shows the DRAM access timing chart.

Note: For details on the timing settings, refer to section 8.6, “Description of Registers.”

MCLK

ASR

CAO

An

RASn

CAS

RE

Dn

CAS

ASC

Column

RSH

WEn

ASC

Column

CAO

ASR

CAS

WEN

Row

Row

RSH

Read

Write

Fig. 8-14-1

DRAM Access Timing Chart

For details on the various timing settings, refer to the description of the memory control register in section 8.6,
“Description of Registers.”

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