Datasheet

Chapter 26 384 KByte Flash Module (S12XFTM384K2V1)
MC9S12XE-Family Reference Manual Rev. 1.25
992 Freescale Semiconductor
26.4.2.4 Read Once Command
The Read Once command provides read access to a reserved 64 byte field (8 phrases) located in the
nonvolatile information register of P-Flash block 0. The Read Once field is programmed using the
Program Once command described in Section 26.4.2.7. The Read Once command must not be executed
from the Flash block containing the Program Once reserved field to avoid code runaway.
Upon clearing CCIF to launch the Read Once command, a Read Once phrase is fetched and stored in the
FCCOB indexed register. The CCIF flag will set after the Read Once operation has completed. Valid
phrase index values for the Read Once command range from 0x0000 to 0x0007. During execution of the
Read Once command, any attempt to read addresses within P-Flash block 0 will return invalid data.
128
Table 26-38. Erase Verify P-Flash Section Command Error Handling
Register Error Bit Error Condition
FSTAT
ACCERR
Set if CCOBIX[2:0] != 010 at command launch
Set if a Load Data Field command sequence is currently active
Set if command not available in current mode (see Table 26-30)
Set if an invalid global address [22:0] is supplied
(1)
1. As defined by the memory map for FTM512K3.
Set if a misaligned phrase address is supplied (global address [2:0] != 000)
Set if the requested section crosses a 256 Kbyte boundary
FPVIOL None
MGSTAT1 Set if any errors have been encountered during the read
(2)
2. As found in the memory map for FTM512K3.
MGSTAT0 Set if any non-correctable errors have been encountered during the read
2
FERSTAT EPVIOLIF None
Table 26-39. Read Once Command FCCOB Requirements
CCOBIX[2:0] FCCOB Parameters
000 0x04 Not Required
001 Read Once phrase index (0x0000 - 0x0007)
010 Read Once word 0 value
011 Read Once word 1 value
100 Read Once word 2 value
101 Read Once word 3 value