
Chapter 3
3.6 Reset
A RESET can be initiated by one of the following
:
A power-on reset.
The RESET pin is at a low condition (level hold).
The Watchdog timer has timed out (if the Watchdog timer is enabled).
Some control registers are not affected by a reset condition. Their status is
unknown during a power-on reset. The contents of the data RAM are also not
initialized. All the bi-directional ports are set as input type during a reset
condition, but the input status are unknown. However, the global interrupt is
enabled during a reset, but all of the timer interrupts are disabled.
When a RESET occurs, the following functions are performed:
The oscillator starts to run (at power-on & wake-up reset)
The program counter (PC) is set to all “0”.
Bits 5
~
7 of R3 (SF) are set to all “0”, i.e., set to program Page 0.
The upper 2 bits of R4 (RSR) are set to “0”, i.e., select RAM Bank 0.
R1 (TCC) and R6 (MTC) are all cleared.
The count value of the Watchdog timer and prescaler are cleared.
R5 (INTC)
:
Bits 0 ~ 5 are cleared, Bit 7 is set.
R8
:
Bits 0 ~ 2 and Bits 4 ~ 6 are all set to “0”.
R10 ~ 12 (Multiplier)
:
All cleared.
IOC5 (Prescaler Control Register)
:
All bits are set to “1”.
IOCD, F (Port 2 ~ 4 I/O Control Registers)
:
All bits are set to “1” (input).
R9 (Bank Selects Special Function Control Register)
:
Set to “0”.
Speech Channels 1 & 2
:
1. RA (MODE)
:
Bit 0 & 1 are set to “0”
2. IOCA & IOCB (DAC outputs)) are set to “0”.
3. IOCC (Sampling Rate) is set to “0”.
Melody Channels 1 &4
:
1. RA (MODE): Bit 0 is set to “0”
2. IOCA (Envelope) is set to “0”.
D/A Converter 1 & 2:
1. RA (MODE): Bit 0, 2, 3 are set to “0,” Bit 4 ~ 6 are set to “1”.
2. IOC6 (Selector) is set to “0”.
26
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System Control
EM60000Series User’s Manual
Содержание EM60000 series
Страница 8: ...Contents viii Contents EM60000 Series User s Manual ...
Страница 24: ...Chapter 2 16 Architecture EM60000 Series User s Manual ...
Страница 54: ...Chapter 4 46 Special Function Control EM60000Series User s Manual ...
Страница 80: ...Chapter 5 72 Instruction Set EM60000Series User s Manual ...