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CHAPTER 19 512 KBIT FLASH MEMORY
19.1
Overview of 512 Kbit Flash Memory
There are three ways of programming and erasing flash memory as follows:
1. Programming and erasing using parallel writer
2. Programming and erasing using serial writer
3. Programming and erasing by executing program
This chapter describes the above "3. Programming and Erasing by Executing Program".
I Overview of 512 Kbit Flash Memory
512 Kbit flash memory is placed in the FF
flash memory I/F circuit is to provide read access and program access from the CPU to flash
memory.
Programming and erasing flash memory are enabled by an instruction from the CPU via the flash
memory I/F circuit. This allows efficient reprogramming and programming data in the mounted
state under CPU control.
Data can be reprogrammed not only by program execution in RAM but also by program execution
in flash memory because of dual operation. In addition, an erase/write and reading of the different
banks (the upper and lower banks) can be executed concurrently.
I Features of 512 Kbit Flash Memory
• 64 Kword x 8 bits/32 Kword x 16 bits (4 K x 4 + 16 K + 8 K x 2 + 4 K x 4) sector configuration
• An erase/program and a read can be executed concurrently in two banks configuration
• Uses automatic program algorithm (Embedded Algorithm
• Erase pause/restart function
• Detects completion of writing/erasing using data polling or toggle bit functions
• Detects completion of writing/erasing by CPU interrupts
• Erase function by sector (any combination of sectors)
• Programming/erase available 10,000 (min.)
• Flash read cycle time (min.): 2 machine cycles
Embedded Algorithm
Note:
The function of the manufacture code and device code to be read is not provided.
These codes cannot be accessed by any command.
I Programming and Erasing Flash Memory
• Programming and erasing flash memory in the same bank cannot be performed at the same
time.
• Data can be programmed into and erased from flash memory by executing either the program
residing in the flash memory or the one copied to RAM from the flash memory.
576
banks on the CPU memory map. The function of the
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is a registered trademark of Advanced Micro Devices, Inc.
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