M68HC16 Z SERIES
REGISTER SUMMARY
USER’S MANUAL
D-25
D.4 Masked ROM Module
The MRM is used only in the MC68HC16Z2 and the MC68HC16Z3.
shows
the MRM address map.
The reset states shown for the MRM registers are for the generic (blank ROM) ver-
sions of the device. Several MRM register bit fields can be user-specified on a custom
masked ROM device. Contact a
Freescale
sales representative for information on or-
dering a custom ROM device.
D.4.1 Masked ROM Module Configuration Register
STOP — Low-Power Stop Mode Enable
The reset state of the STOP bit is the complement of DATA14 state during reset. The
ROM array base address cannot be changed unless the STOP bit is set.
0 = ROM array operates normally.
1 = ROM array operates in low-power stop mode. The ROM array cannot be read
in this mode.
This bit may be read or written at any time.
Table D-21 MRM Address Map
Address
15
0
$YFF820
Masked ROM Module Configuration Register (MRMCR)
$YFF822
Not Used
$YFF824
ROM Array Base Address Register High (ROMBAH)
$YFF826
ROM Array Base Address Register Low (ROMBAL)
$YFF828
Signature Register High (SIGHI)
$YFF82A
Signature Register Low (SIGLO)
$YFF82C
Not Used
$YFF82E
Not Used
$YFF830
ROM Bootstrap Word 0 (ROMBS0)
$YFF832
ROM Bootstrap Word 1 (ROMBS1)
$YFF834
ROM Bootstrap Word 2 (ROMBS2)
$YFF836
ROM Bootstrap Word 3 (ROMBS3)
$YFF838
Not Used
$YFF83A
Not Used
$YFF83C
Not Used
$YFF83E
Not Used
MRMCR — Masked ROM Module Configuration Register
$YFF820
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
STOP
0
0
BOOT
LOCK
EMUL
ASPC[1:0]
WAIT[1:0]
NOT USED
RESET:
DATA14
0
0
1
0
0
1
1
1
1
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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