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22.2
Detail of Flash Memory
In on-board programming, the CPU executes commands for reprogramming or erasing Flash memory. This reprog-
ramming/erase control program should be prepared by the user beforehand. Since Flash memory content cannot
be read while Flash memory is being written or erased, it is necessary to run the reprogram/erase control program
on the built-in RAM. Do not generate interrupt/fault except reset to avoid abnormal program termination.
22.2.1
Function
Flash memory is generally compliant with the JEDEC standards except for some specific functions. Howev-
er; a method of address designation of operation command is different from standard commands.
If write/erase operation is executed, commands are input to flash memory using 32-bit (1-word) store instruc-
tion command. After command input, write or erase operation is automatically executed in inside.
Table 22-4 Flash memory function
Main function
Automatic page program
Automatic chip erase
Automatic block erase
Write/erase protect
Note: In TMPM3V6/M3V4, after Flash programming or Flash Erasing ,it should be Clearing Instruction buffer.
Pls refer "22.1.6.3 FCCR (Flash Interface control register)" for a clear method.
Note: Check the FCSR<RDY_BSY> to make sure each command sequence end such as Flash writing,
Flash Erase, Protection bit program, Protection bit Erase. and then hold for 200 μs or more before read-
ing data from Flash memory or starting instruction fetch.
22.2.2
Operation Mode of Flash Memory
Flash memory provides mainly two types of operation modes;
・ The mode to read memory data (Read mode)
・ The mode to erase or rewrite memory data automatically (Automatic operation mode)
After power-on, after rest or after automatic operation mode is finished normally, Flash memory becomes
read mode. Instruction stored in Flash memory or data read is executed in the read mode.
If commands is input during the read mode, the operation mode becomes the automatic operation. If the com-
mand process is normally finished, the operation mode returns to the read mode except the ID-Read com-
mand. During the automatic operation, data read and instruction execution stored in Flash memory cannot be
performed.
If command process is abnormally finished then the operation mode should forcibly return to read mode.
In this case, use the read command, read/reset command or hardware reset.
22.2.3
Hardware Reset
A hardware reset means a power-on reset or warm reset to use returning to the read mode when the automat-
ic programming/erase operation is forcibly cancelled, or automatic operation abnormally ends.
If the hardware reset occurs during the automatic operation, Flash memory stops the automatic operation
and returns to the read mode. If a hardware reset is generated during Flash memory automatic program/erase
operation, the hardware reset needs 0.5 μs or more reset period regardless of system clock. At this time, it
takes approximately 2 ms until enabling to read after reset. Note that if a hardware reset occurs during the au-
tomatic operation, data write operation is not executed properly. Set write operation again.
Description
Writes data automatically.
Erases the entire area of Flash memory automatically.
Erases a selected block automatically.
The write or erase operation can be individually inhibited for each block.
Page 453
TMPM3V6/M3V4
2019-02-06
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