HD6432621 Hitachi, HD6432621 Datasheet - Page 661

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

19.2.2
When the mode pins and the FWE pin are set in the reset state and a reset-start is executed, the
microcomputer enters an operating mode as shown in figure 19-2. In user mode, flash memory can
be read but not programmed or erased.
The boot, user program and programmer modes are provided as modes to write and erase the flash
memory.
Notes: Only make a transition between user mode and user program mode when the CPU is
FWE = 1
(on-chip ROM
User mode
enabled)
Mode Transitions
not accessing the flash memory.
*1 RAM emulation possible
*2 MD0 = 0, MD1 = 0, MD2 = 0, P14 = 0, P16 = 0, PF0 = 1
On-board programming mode
program mode
FWE = 0
* 1
User
Figure 19-2 Flash Memory State Transitions
MD1 = 1,
MD2 = 1,
FWE = 0
MD1 = 1,
MD2 = 1,
FWE = 1
* 1
RES = 0
RES = 0
MD1 = 1,
MD2 = 0,
FWE = 1
Reset state
Boot mode
RES = 0
* 2
RES = 0
Programmer
mode
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