M16C Datasheet, PDF (194/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Preliminary Specifications REV.B
Mitsubishi microcomputers
Specifications in this manual are tentative and subject to change.
M16C / 6N Group
Usage precaution
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Timer B (pulse period/pulse width measurement mode)
(1) If changing the measurement mode select bit is set after a count is started, the timer Bi interrupt request
bit goes to “1”.
(2) When the first effective edge is input after a count is started, an indeterminate value is transferred to the
reload register. At this time, timer Bi interrupt request is not generated.
A-D Converter
(1) Write to each bit (except bit 6) of A-D control register 0, to each bit of A-D control register 1, and to bit
0 of A-D control register 2 when A-D conversion is stopped (before a trigger occurs).
In particular, when the Vref connection bit is changed from “0” to “1”, start A-D conversion after an
elapse of 1 µs or longer.
(2) When changing A-D operation mode, select analog input pin again.
(3) Using one-shot mode or single sweep mode
Read the correspondence A-D register after confirming A-D conversion is finished. (It is known by A-D
conversion interrupt request bit.)
(4) Using repeat mode, repeat sweep mode 0 or repeat sweep mode 1
Use the undivided main clock as internal CPU clock.
Stop Mode and Wait Mode
(1) When returning from stop mode by hardware reset, RESET pin must be set to “L” level until main clock
oscillation is stabilized.
Interrupts
(1) Reading address 0000016
• When maskable interrupt is occurred, CPU read the interrupt information (the interrupt number
and interrupt request level) in the interrupt sequence.
The interrupt request bit of the certain interrupt written in address 0000016 will then be set to “0”.
Reading address 0000016 by software sets enabled highest priority interrupt source request bit to “0”.
Though the interrupt is generated, the interrupt routine may not be executed.
Do not read address 0000016 by software.
(2) Setting the stack pointer
• The value of the stack pointer immediately after reset is initialized to 000016. Accepting an
interrupt before setting a value in the stack pointer may become a factor of runaway. Be sure to
set a value in the stack pointer before accepting an interrupt.
When using the NMI interrupt, initialize the stack point at the beginning of a program. Concerning
the first instruction immediately after reset, generating any interrupts including the NMI interrupt is
prohibited.
(3) The NMI interrupt
• As for the NMI interrupt pin, an interrupt cannot be prohibited. Connect it to the VCC pin if unused.
Be sure to work on it.
• Do not get either into stop mode or into wait mode with the NMI pin set to “L”.
External ROM version
The external ROM version is operated only in microprocessor mode, so be sure to perform the following:
• Connect CNVss pin to Vcc.
• Fix the processor mode bit to “112”
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