em78p156n ELAN Microelectronics Corp, em78p156n Datasheet - Page 15

• Manufacturer Part Number: em78p156n
• Description: 8-bit Micro-controller
• Manufacturer: ELAN Microelectronics Corp

This specification is subject to change without prior notice.
4.3 TCC/WDT & Prescaler
9. IOCF (Interrupt Mask Register)
An 8-bit counter available as prescaler for the TCC or WDT. The prescaler is available for either the
TCC or WDT only at any given time, and the PAB bit of the CONT register is used to determine the
prescaler assignment. The PSR0~PSR2 bits determine the ratio. The prescaler is cleared each time the
instruction is written to TCC under TCC mode. The WDT and prescaler, when assigned to WDT mode,
are cleared by the “WDTC” or “SLEP” instructions. Fig. 5 depicts the circuit diagram of TCC/WDT.
• R1 (TCC) is an 8-bit timer/counter. The clock source of TCC can be internal or external clock input
(edge selectable from TCC pin). If TCC signal source is from internal clock, TCC will increase by 1 at
every instruction cycle (without prescaler). Referring to Fig. 5, CLK=Fosc/2 or CLK=Fosc/4 application
is determined by the CODE Option bit CLK status. CLK=Fosc/2 is used if CLK bit is "0", and
Fig. 10.
controller. Clearing the ROC will disable the R-option function. If the R-option function is selected,
user must connect the P51 pin or/and P50 pin to VSS with a 430K
Rex is connected/disconnected, the status of P50 (P51) is read as "0"/"1". Refer to Fig. 8.
• Bits 0~3,5 Not used.
• Bit 0 (TCIE) TCIF interrupt enable bit.
• Bit 1 (ICIE) ICIF interrupt enable bit.
• Bit 2 (EXIE) EXIF interrupt enable bit.
• Bits 3~7 Not used.
• Individual interrupt is enabled by setting its associated control bit in the IOCF to "1".
• Global interrupt is enabled by the ENI instruction and is disabled by the DISI instruction. Refer to
• IOCF register is both readable and writable.
Setting the ROC to "1" will enable the status of R-option pins (P50 P51) that are read by the
7
-
0: disable TCIF interrupt
1: enable TCIF interrupt
0: disable ICIF interrupt
1: enable ICIF interrupt
0: disable EXIF interrupt
1: enable EXIF interrupt
6
-
5
-
15
4
-
3
-
EXIE
2
external resistor (Rex). If the
ICIE
1
EM78P156N
OTP ROM
07.29.2004 (V1.2)
TCIE
0