mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 92

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 2 256 Kbyte Flash Module (FTS256K2V1)
2.3.2.4
The unbanked FCNFG register enables the Flash interrupts and gates the security backdoor writes.
CBEIE, CCIE, KEYACC and BKSEL bits are readable and writable while all remaining bits read 0 and
are not writable. KEYACC is only writable if KEYEN (see
(FSEC)”) is set to the enabled state.
92
KEYACC
BKSEL
Reset
CBEIE
Field
CCIE
7
6
5
0
W
R
CBEIE
Command Buffer Empty Interrupt Enable — The CBEIE bit enables an 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
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
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
Block Select — The BKSEL bit indicates which register bank is active.
0 Select register bank associated with Flash block 0.
1 Select register bank associated with Flash block 1.
Flash Configuration Register (FCNFG)
7
0
is set.
is set.
data.
= Unimplemented or Reserved
CCIE
6
0
Figure 2-7. Flash Configuration Register (FCNFG)
Table 2-9. FCNFG Field Descriptions
KEYACC
MC9S12E256 Data Sheet, Rev. 1.08
5
0
4
0
0
Description
Section 2.3.2.2, “Flash Security Register
3
0
0
Section 2.3.2.7, “Flash Status Register
Section 2.3.2.7, “Flash Status Register (FSTAT)”)
2
0
0
Freescale Semiconductor
1
0
0
BKSEL
(FSTAT)”)
0
0