MC9S12C Datasheet, PDF (479/680 Pages) Motorola, Inc – 16-Bit Microcontroller

Chapter 17 16 Kbyte Flash Module (S12FTS16KV1)
Table 17-11. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario⁽¹⁾
0
1
2
3
3
X
X
X
X
1. Allowed transitions marked with X.
17.3.2.6 Flash Status Register (FSTAT)
The FSTAT register defines the status of the Flash command controller and the results of command
execution.
Module Base + 0x0005
R
W
Reset
7
CBEIF
1
6
5
4
3
CCIF
0
PVIOL
ACCERR
2
BLANK
1
0
0
0
0
= Unimplemented or Reserved
Figure 17-10. Flash Status Register (FSTAT)
1
FAIL
0
0
DONE
1
In normal modes, bits CBEIF, PVIOL, and ACCERR are readable and writable, bits CCIF and BLANK
are readable and not writable, remaining bits, including FAIL and DONE, read 0 and are not writable. In
special modes, FAIL is readable and writable while DONE is readable but not writable. FAIL must be clear
in special modes when starting a command write sequence.
Table 17-12. FSTAT Field Descriptions
Field
7
CBEIF
6
CCIF
Description
Command Buffer Empty Interrupt Flag — The CBEIF flag indicates that the address, data and command
buffers are empty so that a new command write sequence can be started. The CBEIF flag is cleared by writing
a 1 to CBEIF. Writing a 0 to the CBEIF flag has no effect on CBEIF. Writing a 0 to CBEIF after writing an aligned
word to the Flash address space but before CBEIF is cleared will abort a command write sequence and cause
the ACCERR flag in the FSTAT register to be set. Writing a 0 to CBEIF outside of a command write sequence
will not set the ACCERR flag. The CBEIF flag is used together with the CBEIE bit in the FCNFG register to
generate an interrupt request (see Figure 17-26).
0 Buffers are full
1 Buffers are ready to accept a new command
Command Complete Interrupt Flag — The CCIF flag indicates that there are no more commands pending. The
CCIF flag is cleared when CBEIF is clear and sets automatically upon completion of all active and pending
commands. The CCIF flag does not set when an active commands completes and a pending command is
fetched from the command buffer. Writing to the CCIF flag has no effect. The CCIF flag is used together with the
CCIE bit in the FCNFG register to generate an interrupt request (see Figure 17-26).
0 Command in progress
1 All commands are completed
Freescale Semiconductor
MC9S12C-Family / MC9S12GC-Family
479
Rev 01.23