IBM EM78P447N manual Ioce WDT Control Register, Wue

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EM78P447N

8-Bit Microcontroller with OTP ROM

4.2.5 IOCE (WDT Control Register)

7

 

6

 

5

 

4

 

3

-

 

ODE

 

WDTE

 

SLPC

 

ROC

 

 

 

 

 

 

 

 

 

21

- -

0

/WUE

Bit 6 (ODE) Control bit is used to enable the open-drain of P76 and P77 pins

0:Disable open-drain output.

1:Enable open-drain output.

The ODE bit can be read and written.

Bit 5 (WDTE) Control bit used to enable Watchdog timer.

The WDTE bit is useful only when ENWDT, the CODE Option bit, is "0". It is only when the ENWDT bit is "0" that WDTE bit. is able to disabled/enabled the WDT.

0:Disable WDT.

1:Enable WDT.

The WDTE bit is not used if ENWDT, the CODE Option bit ENWDT, is "1". That is, if the ENWDT bit is "1", WDT is always disabled no matter what the WDTE bit status is.

The WDTE bit can be read and written.

Bit 4 (SLPC) This bit is set by hardware at the low level trigger of wake-up signal and is cleared by software. SLPC is used to control the oscillator operation. The oscillator is disabled (oscillator is stopped, and the controller enters into SLEEP2 mode) on the high-to-low transition and is enabled (controller is awakened from SLEEP2 mode) on low-to-high transition. In order to ensure the stable output of the oscillator, once the oscillator is enabled again, there is a delay for approximately 18ms1 (oscillator start-up timer, OST) before the next instruction of the program is executed. The OST is always activated by a wake-up event from sleep mode regardless of the Code Option bit ENWDT status is "0" or otherwise. After waking up, the WDT is enabled if the Code Option ENWDT is "1". The block diagram of SLEEP2 mode and wake-up invoked by an input trigger is depicted in Fig. 5. The SLPC bit can be read and written.

Bit 3 (ROC) ROC is used for the R-option. Setting ROC to "1" will enable the status of R-option pins (P70, P71) for the controller to read. Clearing ROC will disable the R-option function. Otherwise, the R-option function is introduced. Users must connect the P71 pin or/and P70 pin to VSS with a 430Kexternal resistor (Rex). If Rex is connected/disconnected with VDD, the status of P70 (P71) will be read as "0"/"1" (refer to Fig. 7(b)). The ROC bit can be read and written.

1 <Note>: Vdd = 5V, set up time period = 16.2ms ± 30%

 

Vdd = 3V, set up time period = 19.6ms ± 30%

 

Product Specification (V1.1) 03.30.2005

13

(This specification is subject to change without further notice)

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Contents EM78P447N Elan Microelectronics Corporation Contents Specification Revision History General Description EM78P447NBWM PIN Assignment EM78P447NAS Pin Description Symbol Pin No Type FunctionEM78P447NAP and EM78P447NAM Pin Description EM78P447NCK and EN78P447NCM Pin Description Power supplyEM78P447NBP and EM78P447NBWM Pin Description EM78P447NDK and EM78P447NDM Pin Description Function Description1 R0 Indirect Addressing Register Operational Registers2 R1 Time Clock /Counter 3 R2 Program Counter & StackFffh Call RET Retl RetiData Memory Configuration 6 R5~R7 Port 5 ~ Port7 5 R4 RAM Select Register7 R8~R1F and R20~R3E General Purpose Register R5, R6 and R7 are I/O registers8 R3F Interrupt Status Register Special Purpose RegistersAccumulator Control RegisterIocb Wake-up Control Register for Port6 3 IOC5 ~ IOC7 I/O Port Control RegisterTCC Rate WDT RateWUE Ioce WDT Control RegisterExie Iocf Interrupt Mask RegisterTCC/WDT & Prescaler TCC and WDT Block DiagramIOD I/O PortsReset Reset and Wake-upSLEEP2 SLEEP1 Usage of Sleep1 and Sleep2 ModeSummary of the Initialized Values for Registers Address Name Reset Type BitExif Tcif R3FISRWUE7 WUE6 WUE5 WUE4 IocbPrevious value before reset Previous status before resetStatus of RST, T, and P of Status Register Events that may Affect the T and P StatusInterrupt Controller Reset Block DiagramMode OscillatorOscillator Modes Summary of Maximum Operating Speeds Crystal Oscillator/Ceramic ResonatorsXTALConditions Fxt max.MHzOscillator Type Frequency Mode C1pF C2pF External RC Oscillator ModeHXT LXTCode Option Register Word Code Option RegisterProtect PR2~PR0 are protect bits, protect type as followingExternal Power On Reset Circuit Power On ConsiderationsCustomer ID Register Word Bit 12~0 Customer’s ID codeResidue-Voltage Protection ResetInstruction Set DAA NOPContw SlepDJZ R Djza RRrca R RRC RAC Test Input/Output W aveform Timing DiagramSymbol Parameter Condition Min Typ Max Unit DC Electrical CharacteristicTa= 25 C, VDD= 5.0V±5%, VSS= Items RatingTa=- -40 C ~ 85 C, VDD=5V ±5%, VSS=0V AC Electrical CharacteristicSymbol Parameter Conditions Min Typ Max Unit Vih, Vil of TCC, /INT, /RESET Pin Device characteristicPort5, Port6 Port7 Voh vs. Ioh,VDD=5V Port5, Port6, and Port7 Voh vs. Ioh, VDD=3V Vol/Iol VDD=5V Vol/Iol VDD=3V Vol/Iol 100 Vol/Iol WDT Cext=100pF, Typical RC OSC Frequency Typical ICC1 and ICC2 vs. Temperature Maximum ICC1 and ICC2 vs. Temperature Typical ISB1 and ISB2 vs. Temperature Maximum ISB1 and ISB2 vs. Temperature EM78P447N HXT ImA Package Type Pin Count Package Size Lead plastic dual inline package(DIP)- 300 milLead plastic dual inline package(DIP)- 600 mil Lead plastic dual inline skinny package(DIP)- 300 mil838 27TYP EM78P447N