Z380 Datasheet, PDF (101/115 Pages) Zilog, Inc. – MICROPROCESSOR

ZILOG
Standby Mode for On-chip Crystal
Oscillator
The previous discussions have been focused on situations
where a direct clock is supplied to the Z380 MPU's CLKI
input. Such a clock may be sourced by an external crystal
with its oscillation circuit. In the case where a crystal is
connected to the Z380 MPU's on-chip oscillator, all standby
functions described earlier apply. Items worth noting are
as follows.
MICROPROCESSOR
1. When standby mode is entered, the feedback path for
the on-chip oscillator is disabled, reducing power con-
sumption.
2. A user can select a warm-up time appropriate for the
crystal being used, by programming the WM2-WM0
bits in the Standby Mode Control Register (SMCR).
Table 6. Z380 MPU On-chip I/O Registers
Register
Mnemonic
Lower Memory Chip Select Register 0
Lower Memory Chip Select Register 1
Upper Memory Chip Select Register 0
Upper Memory Chip Select Register 1
Midrange Memory Chip Select Register 0
Midrange Memory Chip Select Register 1
Midrange Memory Chip Select Register 2
Midrange Memory Chip Select Register 3
LMCS0
LMCS1
UMCS0
UMCS1
MMCS0
MMCS1
MMCS2
MMCS3
Lower Memory Waits Register
Upper Memory Waits Register
Midrange Memory Waits Register 0
Midrange Memory Waits Register 1
Midrange Memory Waits Register 2
Midrange Memory Waits Register 3
I/O Waits Register
Refresh Waits Register
LMWR
UMWR
MMWR0
MMWR1
MMWR2
MMWR3
IOWR
RFWR
Memory Selects Master Enable Register
I/O Bus Control Register 0
I/O Bus Control Register 1
Refresh Register 0
Refresh Register 1
Refresh Register 2
Standby Mode Control Register
Interrupt Enable Register
MSMER
IOCR0
IOCR1
RFSHR 0
RFSHR1
RFSHR2
SMCR
IER
Assigned Vectors Base Register
Trap and Break Register
AVBR
TRPBK
On-Chip I/O Address
00000000H
00000001H
00000002H
00000003H
00000004H
00000005H
00000006H
00000007H
00000008H
00000009H
0000000AH
0000000BH
0000000CH
0000000DH
0000000EH
0000000FH
00000010H
00000011H
00000012H
00000013H
00000014H
00000015H
00000016H
00000017H
00000018H
00000019H
PS010001-0301