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512 Kbyte Flash Module (S12XFTX512K4V2)
BookTitle, Rev. 2.4
Freescale Semiconductor 111
2.3.2.4 Flash Configuration Register (FCNFG)
The FCNFG register enables the Flash interrupts and gates the security backdoor writes.
CBEIE, CCIE and KEYACC bits are readable and writable while all remaining bits read 0 and are not
writable in normal mode. KEYACC is only writable if KEYEN (see Section 2.3.2.2, “Flash Security
Register (FSEC)” is set to the enabled state. BKSEL is readable and writable in special mode to simplify
mass erase and erase verify operations. When writing to the FCNFG register in special mode, all
unimplemented/ reserved bits must be written to 0.
Module Base + 0x0003
76543210
R
CBEIE CCIE KEYACC
00000
W
Reset 00000000
= Unimplemented or Reserved
Figure 2-8. Flash Configuration Register (FCNFG — Normal Mode)
Module Base + 0x0003
76543210
R
CBEIE CCIE KEYACC
000
BKSEL
W
Reset 00000000
= Unimplemented or Reserved
Figure 2-9. Flash Configuration Register (FCNFG — Special Mode)
Table 2-9. FCNFG Field Descriptions
Field Description
7
CBEIE
Command Buffer Empty Interrupt Enable — The CBEIE bit enablesan interrupt in case of an empty command
buffer in the Flash module.
0 Command buffer empty interrupt disabled.
1 An interrupt will be requested whenever the CBEIF flag (see Section 2.3.2.6, “Flash Status Register (FSTAT)”)
is set.
6
CCIE
Command Complete Interrupt Enable — The CCIE bit enables an interrupt in case all commands have been
completed in the Flash module.
0 Command complete interrupt disabled.
1 An interrupt will be requested whenever the CCIF flag (see Section 2.3.2.6, “Flash Status Register (FSTAT)”)
is set.
5
KEYACC
Enable Security Key Writing
0 Flash writes are interpreted as the start of a command write sequence.
1 Writes to Flash array are interpreted as keys to open the backdoor. Reads of the Flash array return invalid
data.
1–0
BKSEL[1:0]
Block Select — The BKSEL[1:0] bits indicates which register bank is active according to Table 2-10.