Operation Modes - NEC V850E/Dx3 Preliminary User's Manual

Chapter 3
ROM mask devices
114
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3.3 Operation Modes

This section describes the operation modes of the CPU and how the modes
are specified.
Flash devices The following operation modes are available for the flash memory devices:
• Normal operation mode
• Flash programming mode
After reset release, the microcontroller starts to fetch instructions from an
internal boot ROM which contains the internal firmware. The firmware checks
the FLMD0 pin, and optionally also the FLMD1 pin, to set the operation mode
after reset release according to Table 3-10.
Table 3-10 Selection of operation modes for flash memory devices
Pins
FLMD0
0
1
Note The FLMD1 pin function is shared with the P07 pin.
Since mask ROM devices do not have any programmable flash memory on-
chip the only operation mode is the normal operation mode.
Caution The FLMD0 pin of ROM mask devices must be set to low level during and after
reset.
Preliminary User's Manual U17566EE1V2UM00
Operation Mode
FLMD1
(P07)
X Normal operation mode (fetch from flash)
0 Flash programming mode
1 Setting prohibited
CPU System Functions