PIC16F688-I/STG Microchip Technology, PIC16F688-I/STG Datasheet - Page 47

• Manufacturer Part Number: PIC16F688-I/STG
• Description: IC PIC MCU FLASH 4KX14 14TSSOP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F688-I/STG

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: UART/USART
• Peripherals: Brown-out Detect/Reset, POR, WDT
• Number Of I /o: 12
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 14-TSSOP
• For Use With: XLT14SS-1 - SOCKET TRANSITION 14DIP/14SSOPAC162061 - HEADER INTRFC MPLAB ICD2 20PINAC162056 - HEADER INTERFACE ICD2 16F688
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

5.0
The Timer0 module is an 8-bit timer/counter with the
following features:
• 8-bit timer/counter register (TMR0)
• 8-bit prescaler (shared with Watchdog Timer)
• Programmable internal or external clock source
• Programmable external clock edge selection
• Interrupt on overflow
Figure 5-1 is a block diagram of the Timer0 module.
FIGURE 5-1:
© 2009 Microchip Technology Inc.
T0CKI
SWDTEN
pin
Note 1:
WDTE
F
INTOSC
OSC
31 kHz
TIMER0 MODULE
T0SE
2:
3:
/4
T0SE, T0CS, PSA, PS<2:0> are bits in the OPTION register.
SWDTEN and WDTPS<3:0> are bits in the WDTCON register.
WDTE bit is in the Configuration Word register.
BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER
Watchdog
Timer
T0CS
0
1
PSA
Prescaler
0
1
16-bit
16
Prescaler
WDTPS<3:0>
8-bit
8
PS<2:0>
5.1
When used as a timer, the Timer0 module can be used
as either an 8-bit timer or an 8-bit counter.
5.1.1
When used as a timer, the Timer0 module will
increment every instruction cycle (without prescaler).
Timer mode is selected by clearing the T0CS bit of the
OPTION register to ‘0’.
When TMR0 is written, the increment is inhibited for
two instruction cycles immediately following the write.
5.1.2
When used as a counter, the Timer0 module will
increment on every rising or falling edge of the T0CKI
pin. The incrementing edge is determined by the T0SE
bit of the OPTION register. Counter mode is selected by
setting the T0CS bit of the OPTION register to ‘1’.
Note:
Timer0 Operation
8-BIT TIMER MODE
The value written to the TMR0 register can
be adjusted, in order to account for the two
instruction cycle delay when TMR0 is
written.
8-BIT COUNTER MODE
PSA
PSA
1
0
1
0
Time-out
Sync
2 Tcy
WDT
PIC16F688
DS41203E-page 45
Data Bus
Set Flag bit T0IF
8
TMR0
on Overflow