MC68F375
CDR MoneT FLASH FOR THE IMB3 (CMFI)
MOTOROLA
REFERENCE MANUAL
Rev. 25 June 03
10-30
10.6.6.2 Program Margin Reads
The CMFI EEPROM provides a program margin read with electrical margin for the pro-
gram state. Program margin reads provide sufficient margin to assure specified data
retention. The program margin read is enabled when SES = 1 and a programming
write has occurred. To increase the access time of the program margin read, the burst
buffer access time shall be 16 clocks instead of the usual number of clocks as deter-
mined by WAIT[1:0] for the first read access. The program margin read and
subsequent verify reads will return a 1 for any bit that has not completely programmed.
Bits that the programming write left in the non-programmed state will read as a 0. Bits
that have completed programming will read as a 0 and update the data in the program-
ming page buffer so that no further programming of those bits will occur. The program
margin read occurs whenever the burst buffer data is invalid. See section 10.6.5 Array Read Operation for information on when the burst buffer is invalid. A program margin
read must be done for all pages that are being programmed after each program pulse.
This requires two program margin reads for each program buffer. The first required
program margin read should be to an address in either the lower or upper 32 bytes of
the program buffer while the second should be to an address in the other 32 bytes.
S4
Program Operation:
High voltage is applied to the array or shadow in-
formation to program the CMFI bit cells.
The pulse width timer is active if SCLKR[2:0]
≠ 0
and HVS can be polled to time the program pulse.
No further programming writes will be accepted.
During programming the CMFI will not generate an
address acknowledge for any array access.
Accesses to the registers are normal register ac-
cesses.
A write to CMFICTL2 can change EHV only.
S1
T7
Master reset
S5
T5
Write EHV = 0, write STOP = 1
or system reset
S5
Program Margin Read Operation:
These reads shall determine if the state of the bits
on the selected page needs further modification by
the program operation.
Once a bit is fully programmed, the data stored in
the program page shall be updated so no further
programming occurs for that bit and the value read
is a 0.
S4
T8
Write EHV = 1.
S1
T9
Write SES = 0 or master reset
Table 10-13 Program Interlock State Descriptions (Continued)
State
Mode
Next
State
Transition Requirement
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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