tmp88fw45afg TOSHIBA Semiconductor CORPORATION, tmp88fw45afg Datasheet - Page 245

• Manufacturer Part Number: tmp88fw45afg
• Description: 8 Bit Microcontroller Tlcs-870/x Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

20.3
20.4
20.4.1
to read from the same address is reversed bit 6 (D6) of the data (toggling between 0 and 1) until the operation is
completed. Therefore, this toggle bit provides a software mechanism to check the completion of each operation.
Usually perform read operations repeatedly for data polling until the same data is read twice from the same address
in the flash memory. After the byte program, chip erase, or security program command sequence is executed, the initial
read of the toggle bit always produces a "1".
performed in the entire flash memory area. Therefore, to perform these operations in the entire flash memory area,
access to the flash memory area by the control program in the BOOTROM or RAM area. (The flash memory program
cannot write to the flash memory.) The serial PROM or MCU mode is used to run the control program in the BOOT-
ROM or RAM area.
20.4.1.1
Note 1: The flash memory can be written or read for each byte unit. Erase operations can be performed either in the entire
Note 2: To rewrite data to Flash memory addresses at which data (including FFH) is already written, make sure to erase
After the byte program, chip erase, and security program command sequence is executed, any consecutive attempts
When the write, erase and security program are set in the flash memory, read and fetch operations cannot be
Toggle Bit (D6)
Access to the Flash Memory Area
ROM area. Since almost of all operations relating to access to the flash memory can be controlled simply by the
communication data of the serial interface (UART), these functions are transparent to the user. For the details of
the serial PROM mode, see “Serial PROM Mode.”
command to execute the control program in the RAM area. The procedures to execute the control program in the
RAM area is shown in "20.4.1.1 How to write to the flash memory by executing the control program in the RAM
area (in the RAM loader mode within the serial PROM mode)".
The serial PROM mode is used to access to the flash memory by the control program provided in the BOOT-
To access to the flash memory by using peripheral functions in the serial PROM mode, run the RAM loader
Flash Memory Control in the Serial PROM Mode
executed in the RAM area.)
area or in units of 4 kbytes, whereas read operations can be performed by an one transfer instruction. However,
the command sequence method is adopted for write and erase operations, requiring several-byte transfer instruc-
tions for each operation.
the existing data by "sector erase" or "chip erase" before rewriting data.
loader mode within the serial PROM mode)
Note 1: Before writing to the flash memory in the RAM area, disable interrupts by setting the interrupt master
(Steps 1 and 2 are controlled by the BOOTROM, and steps 3 to 9 are controlled by the control program
How to write to the flash memory by executing the control program in the RAM area (in the RAM
1. Transfer the write control program to the RAM area in the RAM loader mode.
2. Jump to the RAM area.
3. Disable (DI) the interrupt master enable flag (IMF←"0").
4. Set FLSCR<FLSMD> to "0011B" (to enable command sequence execution).
5. Execute the erase command sequence.
6. Read the same flash memory address twice.
7. Execute the write command sequence.
8. Read the same flash memory address twice.
9. Set FLSCR<FLSMD> to "1100B" (to disable command sequence execution).
enable flag (IMF) to "0". Usually disable interrupts by executing the DI instruction at the head of the write
control program in the RAM area.
(Repeat step 6 until the same data is read by two consecutive reads operations.)
(Repeat step 8 until the same data is read by two consecutive reads operations.)
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