HD6475328-CP10 Datasheet, PDF (147/459 Pages) Hitachi Semiconductor – original Hitachi CMOS microcomputer unit (MCU)

7.2 Wait-State Control Register
The wait-state control register (WCR) is an 8-bit register that specifies the wait mode and the
number of wait states to be inserted. A reset initializes the WCR to specify the programmable
wait mode with three wait states. The WCR is not initialized in the software standby mode.
Bit
7
6
5
4
3
2
1
0
—
—
—
— WMS1 WMS0 WC1 WC0
Initial value
1
1
1
1
0
0
1
1
Read/Write
—
—
—
—
R/W R/W R/W R/W
Bits 7 to 4—Reserved: These bits cannot be modified and are always read as “1.”
Bits 3 and 2—Wait Mode Select 1 and 0 (WMS1 and WMS0): These bits select the wait mode
as shown below.
Bit 3
WMS1
0
0
1
1
Bit 2
WMS0
0
1
0
1
Description
Programmable wait mode (Initial value)
No wait states are inserted, regardless of the wait count.
Pin wait mode
Pin auto-wait mode
Bits 1 and 0—Wait Count (WC1 and WC0): These bits specify the number of wait states to be
inserted.
Wait states are inserted only in bus cycles in which the CPU or DTC accesses an external address.
Bit 1
WC1
0
0
1
1
Bit 0
WC0
0
1
0
1
Description
No wait states are inserted, except in pin wait mode.
1 Wait state in inserted.
2 Wait states are inserted.
3 Wait states are inserted. (Initial value)
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