sh6616 SinoWealth Micro-Electronics Corp. Ltd, sh6616 Datasheet - Page 24

• Manufacturer Part Number: sh6616
• Description: 16k 4-bit Microcontroller
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

8. Interrupt
Three interrupt sources are available on the SH6616:
- Base Timer interrupt (BTMR)
- Timer0 interrupt (TMR0)
- Port falling edge detection interrupt ( PB )
8.1. Interrupt Control Bits and Interrupt Service:
- Interrupt control flags are mapped on $00 through $01 of the system register. They can be accessed or tested by the
8.2. Vector Address and Interrupt Priority
9. System Clock and Oscillation Circuit
The system clock generator produces clock pulses supplied to the CPU and on-chip peripherals.
-Instruction cycle time: 2 µs for 2 MHz clock.
10. HALT or STOP
- After execution of HALT, SH6616 will enter HALT state. In HALT state, the CPU will stop operating, but the peripheral circuit
- After execution of STOP, SH6616 will enter STOP. In STOP, the entire chip (including RC oscillator) will stop operating. If
11. Warm-up Timer
The warm-up timer eliminates an initial oscillation instability in the following two cases:
(1) Power-on reset;
(2) Wake-up from STOP.
Software warm-up is needed for Base Timer start-up.
The warm-up time interval is 32 clock cycles.
- Interrupt request begins when IRQx is set to 1 and IEx is 1. At this time, an interrupt will activate and vector address will
- In HALT, SH6616 will wake up if an interrupt occurs.
- In STOP, SH6616 will wake up if port interrupt occurs or BTM interrupt occurs.
LCD outputs waveform if 32.768Khz LCD clock source is chosen in STOP mode.
32.768Khz clock is actived by setting BTM.2-BTM.0, the Base Timer keeps running even in STOP mode. In the same manner,
(timer) will operate.
program. These flags are cleared to 0 at initialization.
commence from the priority PLA corresponding to the interrupt source. When an interrupt occurs, the PC and CY flags will
be saved in stack memory and jump to an interrupt service vector address. After an interrupt occurs, all interrupt enable flags
(IEx) are automatically reset to 0, so all interrupts are disabled. The IRQx, which caused the interrupt, must be reset by
software in the interrupt service routine. When IEx is set to 1 again, SH6616 can supply multi-level interrupts.
Address
$00
$01
1 (Most)
2
3
4
5 (Least)
Priority
IRQBT
IEBT
Bit 3
IRQT0
Bit 2
IET0
Interrupt source
Bit 1
RESET
BTMR
TMR0
Reserved
-
-
PB
24
IRQP
Bit 0
IEP
Interrupt request flags
Interrupt enable flags
Remarks
SH6616