SH7021 datasheet(116/509 Pages) RENESAS

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Bit 14: IOE

Description

Area 6 is external memory space (initial value)

Area 6 is an address/data multiplexed I/O area

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Bit 13 (warp mode bit (WARP)): WARP selects warp or normal mode. 0 sets it for normal

mode and 1 sets it for warp mode. In warp mode, some external accesses are carried out in

parallel with internal access.

Bit 13: WARP

Description

Normal mode: External and internal accesses are not simultaneously

performed (initial value)

Warp mode: External and internal accesses are simultaneously

performed

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Bit 12 (RD duty (RDDTY)): RDDTY selects 35% or 50% of the T1 state as the high-level duty

cycle ratio of signal

RD. 0 sets it for 50%, 1 sets it for 35%. Only set to 1 when the operating

frequency is a minimum of 10 MHz.

Bit 12: RDDTY

Description

RD signal high-level duty cycle is 50% of T1 state (initial value)

RD signal high-level duty cycle is 35% of T1 state

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Bit 11 (byte access select (BAS)): BAS selects whether byte access control signals are

WRH,

WRL, and A0, or LBS, WR and HBS during word space accesses. When this bit is cleared to

WRH, WRL, and A0 signals are valid; when set to 1, LBS, WR, and HBS, signals are valid.

Bit 11: BAS

Description

WRH, WRL, and A0 enabled (initial value)

LBS, WR, and HBS enabled

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Bits 10–0 (reserved): These bits always read as 0. The write value should always be 0.

8.2.2

Wait State Control Register 1 (WCR1)

Wait state control register 1 is a 16-bit read/write register that controls the number of states for

accessing each area and the whether wait states are used. WCR1 is initialized to H'FFFF by a

power-on reset. It is not initialized by a manual reset or by the standby mode.

SH7021 Datasheet(PDF) 116 Page - Renesas Technology Corp