PIC16C71-04/P Microchip Technology Inc., PIC16C71-04/P Datasheet - Page 34

• Manufacturer Part Number: PIC16C71-04/P
• Description: 18 PIN, 1.75 KB OTP, 36 RAM, 13 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16C71-04/P

• A/d Inputs: 4-Channel, 8-Bit
• Cpu Speed: 5 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 13
• Memory Type: OTP
• Number Of Bits: 8
• Package Type: 18-pin PDIP
• Programmable Memory: 1.75K Bytes
• Ram Size: 36 Bytes
• Speed: 20 MHz
• Timers: 1-8-bit
• Voltage, Range: 3-6 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC16C71X
6.3
An 8-bit counter is available as a prescaler for the
Timer0 module, or as a postscaler for the Watchdog
Timer, respectively (Figure 6-6). For simplicity, this
counter is being referred to as “prescaler” throughout
this data sheet. Note that there is only one prescaler
available which is mutually exclusively shared between
the Timer0 module and the Watchdog Timer. Thus, a
prescaler assignment for the Timer0 module means
that there is no prescaler for the Watchdog Timer, and
vice-versa.
The PSA and PS2:PS0 bits (OPTION<3:0>) determine
the prescaler assignment and prescale ratio.
FIGURE 6-6:
DS30272A-page 34
RA4/T0CKI
CLKOUT (=Fosc/4)
WDT Enable bit
pin
Watchdog
Timer
Prescaler
Note: T0CS, T0SE, PSA, PS2:PS0 are (OPTION<5:0>).
BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER
T0SE
0
1
PSA
M
U
X
0
1
T0CS
M
U
X
0
8-bit Prescaler
8 - to - 1MUX
Time-out
8
M U X
WDT
1
0
1
PSA
M
U
X
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g. CLRF 1, MOVWF 1,
BSF
assigned to WDT, a CLRWDT instruction will clear the
prescaler along with the Watchdog Timer. The pres-
caler is not readable or writable.
Note:
PSA
PS2:PS0
1,x....etc.) will clear the prescaler. When
Cycles
SYNC
Writing to TMR0 when the prescaler is
assigned to Timer0 will clear the prescaler
count, but will not change the prescaler
assignment.
2
1997 Microchip Technology Inc.
TMR0 reg
Data Bus
8
Set flag bit T0IF
on Overflow