MPC555CME Freescale Semiconductor, MPC555CME Datasheet - Page 682

• 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

19.7.7 Starting and Ending a Program or Erase Sequence
MPC555
USER’S MANUAL
In this example system clock frequency = 40 MHz; the system clock period is therefore
25 ns.
The SES bit is used to signal the start and end of a program or erase sequence. At the
start of a program or erase sequence, SES is set (written to a one). This locks
PROTECT[0:7], SCLKR[0:2], CLKPE[0:1], CLKPM[0:6], BLOCK[0:7], CSC and PE. If
PE = 0 and SES = 1, SIE is write-locked. At this point the CMF EEPROM is ready to
receive either the programming writes or the erase interlock write.
If the PE bit is a zero, the CMF BIU accepts programming writes to the CMF array ad-
dress for programming. The first programming write selects the program page offset
address (ADDR[17:25]) to be programmed along with the data for the programming
buffers at the location written. All programming writes after the first will update the pro-
gram buffers using the lower address (ADDR[26:29]) and the block address (AD-
DR[14:16]) to select the program page buffers to receive the data. For further
information see section
ten to the program buffers the EHV bit is set (written to a one) to start the programming
pulse and lock out further programming writes.
If the PE bit = 1, the CMF BIU accepts writes to any CMF array address as an erase-
interlock write. An erase interlock write is required before the EHV bit can be set.
At the end of the program or erase operation the SES bit must be cleared (written to a
zero) to return to normal operation and release the program buffers, PROTECT[0:7],
SCLKR[0:2], CLKPE[0:1], CLKPM[0:6], BLOCK[0:7], CSC and PE.
The default reset state of SES is not configured for program or erase operation (SES
= 0).
1. Determine SCLKR:
2. Determine CLKPE:
3. Determine CLKPM:
4. Check the results:
/
MPC556
From
From
ponents in the range of N = 5, 6, 7, or 8. While any of these values can be se-
lected CLKPE[0:1] = 0b00, N = 5, will be used for the example.
Using the selected values of N and R in the pulse width equation and solving
for M yields M = 8. Therefore, CLKPM[0:6] = 0x7 (0b0000111).
Pulse Width = System Clock Period
Using SCLKR[0:2] = 0b101, CLKPE[0:1] = 0b00, CLKPM[0:6] = 0b0000111
and PE = 0 at 40 MHz system clock. Pulse Width = 25 ns • 4 • 2
program pulse.
The erase interlock write is a write to any CMF EEPROM array loca-
tion after SES is set and PE = 1.
Table 19-12
Table 19-13
19.2.2.2 Program Page
a 40 MHz system clock uses SCLKR[0:2] = 0b101, R = 4.
a 25.6 µs program pulse, PE = 0, can be generated by ex-
CDR MoneT FLASH EEPROM
Rev. 15 October 2000
NOTE
•
R
•
Buffers. After the data has been writ-
2
N
•
M
5
• 8 = 25.6 µs
MOTOROLA
19-30