sh6636 SinoWealth Micro-Electronics Corp. Ltd, sh6636 Datasheet - Page 11

• Manufacturer Part Number: sh6636
• Description: Mask 4-bit Microcontroller With Remote Control Carrier Synthesizer
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

(b) Port Interrupt ( PBC )
The PORTB and PORTC are used as port interrupt sources. Since PORT I/O is a bit programmable I/O, only the input port can
generate an external interrupt. Any one of the PORTB and PORTC input pin transitions from V
interrupt request. Further falling edge transition will not be able to make an interrupt request until all of the input pins have
returned to V
diagram.
9. HALT and STOP mode
After execution of the HALT instruction, SH6636 will enter HALT mode.
In HALT mode, the CPU will stop operating. But peripheral circuit (timer) will keep operating.
After the execution of the STOP instruction, SH6636 will enter STOP mode.
In STOP mode, the entire chip (including oscillator) will stop operating.
In HALT mode, SH6636 can be woken up if any interrupt occurs.
In STOP mode, SH6636 can be woken up if a port interrupt occurs.
10 Warm-up Timer
The SH6636 has a built in oscillator warm-up timer to eliminate an unstable state of initial oscillation when the oscillator starts
oscillating under the following conditions:
(1) Power on reset
(2) Wake-up from stop mode
Warm-up time interval (F
(1) Power on reset interval is as long as the initial oscillator’s frequency mode warm-up timer interval.
(2) 2MHz ceramic oscillator wake-up:
When SH6636 operates in 455KHz frequency, the warm-up time interval is 1.13 ms.
When SH6636 operates in 2MHz frequency, the warm-up time interval is 256 s.
DD
. This can also be used to wake the CPU from STOP mode. The following is the port interrupt function block-
OSC/
PORTC.3
PORTC.2
PORTC.1
PC3OUT
PC2OUT
PC1OUT
PORTC.0
PORTB.3
PORTB.2
PORTB.1
PORTB.0
PC0OUT
PB3OUT
PB2OUT
PB1OUT
PB0OUT
512 cycles of oscillator):
Figure 6. PORT Interrupt Block Diagram
11
FALLING EDGE
DETECTION
INTERRUPT
DD
PORT
to GND will generate an
SH6636