MC9S12NE64CPVE Datasheet, PDF (82/554 Pages) Freescale Semiconductor, Inc – MC9S12NE64 Device Overview

Chapter 2 64 Kbyte Flash Module (S12FTS64KV3)
CBEIF, PVIOL, and ACCERR are readable and writable, CCIF and BLANK are readable and not writable,
remaining bits read 0and are not writable in normal mode. FAIL is readable and writable in special mode.
FAIL must be clear when starting a command write sequence.
Table 2-14. FSTAT Field Descriptions
Field
Description
7
CBEIF
6
CCIF
5
PVIOL
4
ACCERR
2
BLANK
1
FAIL
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 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 2-28).
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 on CCIF. The CCIF flag is used together
with the CCIE bit in the FCNFG register to generate an interrupt request (see Figure 2-28).
0 Command in progress.
1 All commands are completed.
Protection Violation Flag — The PVIOL flag indicates an attempt was made to program or erase an address
in a protected area of the Flash block during a command write sequence. The PVIOL flag is cleared by writing a
1 to PVIOL. Writing a 0 to the PVIOL flag has no effect on PVIOL. While PVIOL is set, it is not possible to launch
a command or start a command write sequence.
0 No failure.
1 A protection violation has occurred.
Access Error Flag — The ACCERR flag indicates an illegal access to the Flash array caused by either a
violation of the command write sequence, issuing an illegal command (illegal combination of the CMDBx bits in
the FCMD register), launching the sector erase abort command terminating a sector erase operation early or the
execution of a CPU STOP instruction while a command is executing (CCIF = 0). The ACCERR flag is cleared by
writing a 1 to ACCERR. Writing a 0 to the ACCERR flag has no effect on ACCERR. While ACCERR is set, it is
not possible to launch a command or start a command write sequence. If ACCERR is set by an erase verify
operation or a data compress operation, any buffered command will not launch.
0 No access error detected.
1 Access error has occurred.
Erase Verify Operation Status Flag — When the CCIF flag is set after completion of an erase verify command,
the BLANK flag indicates the result of the erase verify operation. The BLANK flag is cleared by the Flash module
when CBEIF is cleared as part of a new valid command write sequence. Writing to the BLANK flag has no effect
on BLANK.
0 Flash block verified as not erased.
1 Flash block verified as erased.
Flag Indicating a Failed Flash Operation — The FAIL flag will set if the erase verify operation fails (Flash block
verified as not erased). The FAIL flag is cleared by writing a 1 to FAIL. Writing a 0 to the FAIL flag has no effect
on FAIL.
0 Flash operation completed without error.
1 Flash operation failed.
MC9S12NE64 Data Sheet, Rev. 1.1
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Freescale Semiconductor