MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 683

• 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

19.7.8 Controlling the Program/Erase Voltage
19.8 Censored and Non-Censored Accesses
19.8.1 Uncensored Mode
19.8.2 Censored Mode
MPC555
USER’S MANUAL
The external program or erase enable pin (EPEE) and EHV are used to control the ap-
plication of the program or erase voltage to the CMF EEPROM module. High voltage
operations to the CMF EEPROM array, special MoneT shadow locations or FLASH
NVM registers can occur only if EHV = 1 and EPEE = 1.
Only after the correct hardware and software interlocks have been applied to the CMF
EEPROM can EHV be set. Once EHV is set SES cannot be changed and attempts to
read the array will not be acknowledged.
The default reset state of EHV disables program or erase pulses (EHV = 0). A master
reset while EHV = 1 terminates the high voltage operation, and CMF generates the re-
quired sequence to disable the high voltage without damage to the high voltage cir-
cuits. A soft reset or disabling the internal memory map clears EHV, terminating the
high voltage pulse.
The MPC555 / MPC556 always operates in one of two modes: censored or uncen-
sored.
Uncensored mode provides no censorship. In uncensored mode the FIC, ACCESS,
and CENSOR[0:1] bits are irrelevant. The MPC555 / MPC556 operates in uncensored
mode unless a specific event occurs to place the device in censored mode.
The MPC555 / MPC556 enters censored mode in response to any of the following
events:
The CMF EEPROM censorship mechanism provides several censorship levels. Four
bits in CMFMCR are used to configure the CMF censorship level. These bits are listed
in
In censored mode, the ACCESS and CENSOR bits work together according to
19-15.
Table
• Booting from external memory
• Any CMF array access from an external master
• Entering background debug mode.
/
ACCESS
FIC
CENSOR[0:1]
MPC556
19-14.
Enables a CMF EEPROM to bypass the censorship
Overrides CENSOR[0:1] to force information censorship if ACCESS = 0
Determine the censorship level of the CMF
Table 19-14 Censorship Control Bits
CDR MoneT FLASH EEPROM
Rev. 15 October 2000
MOTOROLA
Table
19-31