MPC555
/
MPC556
CDR MoneT FLASH EEPROM
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
19-6
Table 19-2 CMFMCR Bit Descriptions
Bit(s)
Name
Description
0
LOCK
Lock control. When the LOCK control bit is cleared, the following bits are locked: FIC,
SUPV[0:7], DATA[0:7] and PROTECT[0:7]. Writes to these bits will have no effect.
In normal operation, once the LOCK bit is cleared, the write-lock can only be disabled again by
a master reset. The LOCK bit is writable if the device is in background debug mode and CSC = 0.
0 = Write-locked registers are protected
1 = Write-lock is disabled (reset state)
Warning
:
If the lock protection mechanism is enabled (LOCK = 0) before the PROTECT[0:7] bits
are cleared, the device must use background debug mode to program or erase the CMF array.
1:2
—
Reserved
3
FIC
Force information censorship for access development. Refer to
for details.
The FIC bit is write protected by the LOCK. If FIC = 1 it cannot be cleared except by a hard reset.
0 = Normal CMF censorship operation
1 = Forces the CMF into information censorship mode, unless ACCESS = 1
4
SIE
Shadow information enable. Refer to
for details.
The SIE bit is write protected by the SES bit for programming operation. Writes have no effect
if (SES = 1 and PE = 0). The SIE bit can be read whenever the registers are enabled.
0 = Normal array access
1 = Disables normal array access and selects the shadow information
5
ACCESS
Enable uncensored access. Refer to
19.8 Censored and Non-Censored Accesses
for details.
Writes to this bit have no effect when CSC = 1. This bit can be set only when the MCU is in un-
censored mode.
0 = Censored CMF array access allowed only if the CMF censorship is no censorship, (FIC = 0
and CENSOR[0]
≠
CENSOR[1])
1 = Allows all CMF array access.
6:7
CENSOR
Censor accesses. The value of these bits is determined by the state of two NVM bits in two spe-
cial NVM fuses. Refer to
19.8 Censored and Non-Censored Accesses
for details.
The default reset state of CENSOR is user defined by the FLASH NVM register bits.
00 = Cleared censorship, CMF array access allowed only if device is in uncensored mode or
ACCESS = 1
01 = No censorship, All CMF array accesses allowed
10 = No censorship, All CMF array accesses allowed
11 = Information censorship, CMF array access allowed only if device is in uncensored mode or
ACCESS = 1
8:15
SUPV[0:7]
Supervisor space. Each array block can be mapped into supervisor or unrestricted address
space. When an array block is mapped into supervisor address space, only supervisor accesses
are allowed. A user access to a location in supervisor address space will result in a data error
exception. When an array block is mapped into unrestricted address space, both supervisor and
user accesses are allowed.
The SUPV[0:7] bits are write protected by the LOCK and CSC bits. Writes will have no effect if
LOCK=0 or CSC=1.
0 = Array block M is placed in unrestricted address space
1 = Array block M is placed in supervisor address space (reset value)
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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