HD6433044 Datasheet, PDF (654/867 Pages) Hitachi Semiconductor – Hitachi Single-Chip Microcomputer

20.2.2 Module Standby Control Register (MSTCR)
MSTCR is an 8-bit readable/writable register that controls output of the system clock (ø). It also
controls the module standby function, which places individual on-chip supporting modules in the
standby state. Module standby can be designated for the ITU, SCI0, SCI1, DMAC, refresh
controller, and A/D converter modules.
Bit
Initial value
Read/Write
7
PSTOP
0
R/W
6
5
4
3
2
1
0
— MSTOP5 MSTOP4 MSTOP3 MSTOP2 MSTOP1 MSTOP0
1
0
0
0
0
0
0
—
R/W R/W R/W R/W R/W R/W
Reserved bit
ø clock stop
Enables or disables
output of the system clock
Module standby 5 to 0
These bits select modules
to be placed in standby
MSTCR is initialized to H'40 by a reset and in hardware standby mode. It is not initialized in
software standby mode.
Bit 7—ø Clock Stop (PSTOP): Enables or disables output of the system clock (ø).
Bit 1
PSTOP Description
0
System clock output is enabled
1
System clock output is disabled
(Initial value)
Bit 6—Reserved: Read-only bit, always read as 1.
Bit 5—Module Standby 5 (MSTOP5): Selects whether to place the ITU in standby.
Bit 5
MSTOP5 Description
0
ITU operates normally
1
ITU is in standby state
(Initial value)
645