MC68F375
MASK ROM MODULE
MOTOROLA
REFERENCE MANUAL
Rev. 25 June 03
12-3
12.3.2.1 ROM Array Addressing
The array may be specified to reside in supervisor space to restrict access to supervi-
sor only, or it may be specified to exist in unrestricted space to allow access by both
user and supervisor programs. The array may also be configured to respond to pro-
gram space accesses only or to both data and program space accesses.
The BIU of the ROM module compares internal address [23:13] of the IMB3 with ROM-
BAH, ROMBAL[23:13]. If they match, the remaining address bits and ISIZ[1:0] are
used to access the ROM location in the array. Function codes are also checked for the
correct access rights. If the array is specified to exist in supervisor space, user
accesses will be ignored allowing an external device to respond to the address. If the
array is specified to exist in unrestricted space, it will respond to both user and super-
visor accesses. If the array is specified to exist in program space only, data space
accesses to the array will be ignored allowing implementation of separate data and
program space address maps."
12.4 ROM Module Control and Configuration Registers
This section describes the ROM control and configuration registers. Each register field
is described in detail with regard to operation. The ROM module register map is shown
12.4.1 Module Configuration Register (ROMMCR)
The ROM module configuration register is used to control the operation of the ROM
array and provide status information. It also provides the production tester and the cus-
tomer with configuration information.
Table 12-1 ROM Module Register Map
Access
Address1
NOTES:
1. Y = M111, where M is the logic state of the module mapping (MM) bit in the SCIM2E configuration
register (SCIMMCR).
15
8
7
0
S
0xYF F820
ROM Module Configuration Register (ROMMCR)
S
0xYF F824
ROM Base Address High Register (ROMBAH)
S
0xYF F826
ROM Base Address Low Register (ROMBAL)
S
0xYF F828
ROM Signature High Register (SIGHI)
S0xYF F82A
ROM Signature Low Register (SIGLO)
S
0xYF F830,
0xYF F832,
0xYF F834,
0xYF F836
ROM Bootstrap Information Words (ROMBS[0:4])
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
..
.