tmp89fm42 TOSHIBA Semiconductor CORPORATION, tmp89fm42 Datasheet - Page 328

• Manufacturer Part Number: tmp89fm42
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

21.4 Toggle Bit (D6)
21. Flash Memory
RA003
21.4 Toggle Bit (D6)
21.3.4 Product ID entry
21.3.5 Product ID exit
21.3.6 Security program
of the 6th bit (D6) in data read by a read operation is reversed each time a read is performed. This bit reversal can be
used as a software mechanism for checking the completion of each operation. Normally, perform read operations
twice on the same address in the flash memory, and perform polling until the same data is read from the flash mem-
ory.
bit read by the first read operation is always "1".
After the flash memory write, the chip erase, and the security program command sequence are executed, the value
After the flash memory write, the chip erase, and the security program command sequence are executed, the toggle
Note 1: If FLSCR1<FLSMD> is set to "disable", the toggle bit is not reversed.
Note 2: Do not read the toggle bit by using a 16-bit transfer instruction. If the toggle bit is read using a 16-bit transfer
Note 3: Because the instruction cycle is longer than the write time in SLOW mode, the value is not reversed, even if the
uct ID mode, the vendor ID, flash ID and security status can be read from the flash memory.
the flash memory overwrite command and the RAM loader command cannot be executed in serial PROM
mode.
enabled or disabled, read 0xFF7F in product ID mode. Refer to Table 21-4 for further details. The time needed
to enable or disable the security program is 40 Ps maximum. The next command sequence cannot be executed
until the security program setting is completed. To check the completion of the security program setting, per-
form read operations twice on the same address in the flash memory, and perform polling until the same data is
read. When the security program setting is being made, bit 6 is reversed each time a read is performed.
This command activates the product ID mode. If an instruction to read the flash memory is executed in Prod-
This command is used to exit the Product ID mode.
If the security program is enabled, the flash memory is write and read protected in parallel PROM mode, and
To disable the security program, the chip erase must be performed. To check whether the security program is
instruction, the toggle bit does not function properly.
toggle bit is read right after the Byte Program is performed.
Table 21-4 Values to Be Read in Product ID Mode
Address
0xF000
0xF001
0xFF7F
Vendor ID
Flash ID
Security status
Meaning
Page 314
0x98
0xFF:
Other than 0xFF: Security program enabled
0x4D
Security program disabled
Read value
TMP89FM42