SH7708 Datasheet, PDF (317/633 Pages) Renesas Technology Corp – SuperH™ RISC engine

10.4.4 PCMCIA Area Access
In the SH7708 Series (SH7708, SH7708S, SH7708R), if an SDRAM auto-refresh (CAS-before-
RAS) request occurs during an area 6 PCMCIA area access, CS6 is simultaneously asserted, in
addition to the CS signal for the area to be accessed, when the auto-refresh is performed.
If the following specifications are made, CS3 and CS6 will be asserted simultaneously:
Area 3: SDRAM
Area 6: PCMCIA
CS6 remains asserted until the end of the following PCMCIA bus cycle.
CKIO
CS3
RAS
BS
CS6
CS (CS3) asserted
in CAS-before-RAS
refresh
Auto-refresh
cycle
PCMCIA area CS
(CS6) asserted
PCMCIA cycle
Restrictions: When using PCMCIA in area 6 and also using SDRAM, the area 6 CS signal (CS6)
may be asserted earlier than usual, at the same time as the preceding auto-refresh cycle.
Remedy: This anomaly occurs only in area 6. There is no problem with area 5.
Therefore, if use of both SDRAM and PCMCIA in the system is being considered, area 5 should
be used.
If area 6 is used, the system design should allow for CS to be asserted early without causing any
problems.
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