24.4.10.7 Read Once Command
The Read Once command provides read access to a reserved 64-byte field located in the
program flash 0 IFR (see
). Access to
the Program Once field is via 16 records, each 4 bytes long. The Program Once field is
programmed using the Program Once command described in
.
Table 24-42. Read Once Command FCCOB Requirements
FCCOB Number
FCCOB Contents [7:0]
0
0x41 (RDONCE)
1
Program Once record index (0x00 - 0x0F)
2
Not used
3
Not used
Returned Values
4
Program Once byte 0 value
5
Program Once byte 1 value
6
Program Once byte 2 value
7
Program Once byte 3 value
After clearing CCIF to launch the Read Once command, a 4-byte Program Once record is
read from the program flash IFR and stored in the FCCOB register. The CCIF flag is set
after the Read Once operation completes. Valid record index values for the Read Once
command range from 0x00 to 0x0F. During execution of the Read Once command, any
attempt to read addresses within the program flash block containing this 64-byte field
returns invalid data. The Read Once command can be executed any number of times.
Table 24-43. Read Once Command Error Handling
Error Condition
Error Bit
Command not available in current mode/security
FSTAT[ACCERR]
An invalid record index is supplied
FSTAT[ACCERR]
24.4.10.8 Program Once Command
The Program Once command enables programming to a reserved 64-byte field in the
program flash 0 IFR (see
). Access to
the Program Once field is via 16 records, each 4 bytes long. The Program Once field can
be read using the Read Once command (see
Resource command (see
). Each Program Once record can be
programmed only once since the program flash 0 IFR cannot be erased.
Functional Description
KL02 Sub-Family Reference Manual, Rev. 2.1, July 2013
332
Freescale Semiconductor, Inc.
