MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 684

• Manufacturer Part Number: MPC555CME
• Description: KIT EVALUATION FOR MPC555
• Manufacturer: Freescale Semiconductor
• Type: Microcontrollerr

Specifications of MPC555CME

• Contents: Module Board, Installation Guide, Power Supply, Cable, Software and more
• Processor To Be Evaluated: MPC555
• Data Bus Width: 32 bit
• Interface Type: RS-232
• For Use With/related Products: MPC555
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

19.8.3 Device Modes and Censorship Status
MPC555
USER’S MANUAL
There are two states of censorship: information censorship (CENSOR[0:1] = 11) and
cleared censorship (CENSOR[0:1] = 00). In the information censorship state the entire
CMF array must be erased to clear CENSOR[0:1]. In the cleared censorship or no cen-
sorship states the bits in CENSOR[0:1] may be set without modifying the information
in the CMF array. When FIC=1, the CENSOR bits have no effect upon censorship.
While the device is in uncensored mode, ACCESS may be set to allow the device to
enter censored mode and still access the CMF array. ACCESS may not be set while
the device is in censored mode but may be cleared.
The default reset state of ACCESS is zero, so that FIC and CENSOR[0:1] control the
level of censorship to the CMF EEPROM array. All accesses to the CMF EEPROM
array are allowed if ACCESS=1.
If an access is attempted when the device is in censored mode and the following con-
dition holds, the CMF EEPROM module disallows access to the array and signals a
bus error:
If CENSOR[0:1] is in the no-censorship state, however (CENSOR[0]
the CMF EEPROM module recognizes accesses to its address space.
When FIC = 1, the CENSOR bits have no effect upon censorship. If ((FIC = 1) and (AC-
CESS = 0)) the CMF is in information censorship mode. If ((FIC = 1) and (ACCESS =
1)), the CMF is in normal access mode. This arrangement aids in the development of
custom techniques for controlling the ACCESS bit without setting CENSOR[0:1] to the
information censorship state. Using FIC to force information censorship allows testing
of the hardware and software for setting ACCESS without setting CENSOR[0:1] = 11.
The default reset state of FIC is normal censorship operation (FIC = 0).
Table 19-16
the ACCESS, FIC, and CENSOR[0:1] bits.
When booting from the internal flash, the default state is #8 unless BDM was entered,
or a slave access to the MPC555 / MPC556 occurred. When any of these three con-
ditions occur, then the state of CENSOR[0:1] determine whether the flash array can
be accessed:
ACCESS
1. BDM is active
2. Accessing the MPC555 / MPC556 flash via a slave mode read
3. Booting from an external memory
0
0
0
1
/
MPC556
((CENSOR[0] = CENSOR[1])|(FIC = 1)) AND (ACCESS = 0)
summarizes the various combinations of censorship mode and states of
CENSOR[0:1]
01 or 10
XX
11
00
Table 19-15 Levels of Censorship
Information censorship, No CMF array accesses allowed
No censorship, CMF array accesses allowed
Cleared censorship, No CMF array accesses allowed
No censorship, CMF array accesses allowed
CDR MoneT FLASH EEPROM
Rev. 15 October 2000
Description
≠
CENSOR[1]),
MOTOROLA
19-32