FLASH MEMORY VERSION
7902 Group User’s Manual
20-16
20.2 Flash memory CPU reprogramming mode
20.2.2 Status register
The programming and erase operations for the internal flash memory are controlled by the write state
machine in the internal flash memory (hereafter referred to WSM). The status register indicates the operating
status of the WSM and the completion states (normal or abnormal) of the programming and erase operations.
For details of abnormal endings (errors), refer to section “20.2.6 Full status check.”
Table 20.2.2 lists the bit definition of the status register.
The contents of the status register can be read out by the read status register command. (Refer to section
“20.2.5 Software commands.”)
Symbol
(Data bus)
Status
Definition
“0”
“1”
—
Error <Excessive programming error>
Error<Programming error>
Error<Erase error>
—
READY
SR.0 (D0)
SR.1 (D1)
SR.2 (D2)
SR.3 (D3)
SR.4 (D4)
SR.5 (D5)
SR.6 (D6)
SR.7 (D7)
—
Block Status After Programming
Block Status
Erase Status
—
Write State Machine (WSM) Status
—
Terminated normally.
—
BUSY
Data bus: Indicates the data bus to be read out when the read status register command has been executed.
Table 20.2.2 Bit definition of status register
(1) Block status after programming bit (SR.3)
When an excessive programming error has occurred, this bit is set to “1” upon completion of the page
programming. Additionally, this bit is cleared to “0” by executing the clear status register command.
This bit is also cleared to “0” at reset.
(2) Programming status bit (SR.4)
This bit is set to “1” if a programming error has occurred during the automatic programming (the page
programming or lock bit programming) operation and cleared to “0” by executing the clear status
register command. This bit is also cleared to “0” at reset.
(3) Erase status bit (SR.5)
This bit is set to “1” if an erase error has occurred during the automatic erase (the block erase or
erase all unlocked block) operation and cleared to “0” by executing the clear status register command.
This bit is also cleared to “0” at reset.
(4) Write state machine (WSM) bit (SR.7)
This bit is used to indicate the operating status of the WSM. It is “0” during the automatic programming
or erase operation and set to “1” upon completion of these operations.
This bit also changes during the execution of the page programming, block erase, erase all unlocked
block, or the lock bit programming command, but this bit does not change by another command. This
bit is set to “1” at reset.