PIC16F913T-I/SO Microchip Technology, PIC16F913T-I/SO Datasheet - Page 4

• Manufacturer Part Number: PIC16F913T-I/SO
• Description: IC,MICROCONTROLLER,8-BIT,PIC CPU,CMOS,SOP,28PIN,PLASTIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F913T-I/SO

• Rohs Compliant: YES
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 24
• 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 5x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-SOIC (7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

PIC16F91X/946
3. Module: Asynchronous Timer1
EXAMPLE 1:
DS80238C-page 4
Update:
This Errata supersedes Errata DS80329.
When TImer1 is started or updated, the timer
needs to see a falling edge from the external clock
source before a rising edge can increment the
counter. If writes to TMR1H and TMR1L are not
completed while the external clock pulse is still
high, Timer1 will not count the first clock pulse after
the update.
Affected Silicon Revisions
PIC16F913/914
PIC16F916/917
PIC16F946
BTFSC
GOTO
BTFSS
GOTO
BCF
BSF
BCF
BSF
BCF
Critical Timing of code sequence for instructions following last write to TMR1L or TMR1H.
A0
A0
A0
X
X
X
A1
A1
A1
X
X
X
TMR1L,0
$-1
TMR1L,0
$-1
T1CON,TMR1CS
TMR1H,7
T1CON,TMR1ON
T1CON,TMR1CS
T1CON,TMR1ON
A2
A2
A2
X
X
X
A3
B0
X
X
B1
X
;Timer has just incremented, 31 μs before next rising edge to
;complete reload
;Select HFINTOSC for Timer1
;Timer1 high byte 0x80
;Timer1 off
;Select external crystal
;Timer1 on
B2
X
B3
X
When using an external crystal, the pulse width
from rising to falling edge is temperature
dependent and may decrease with temperature.
As a result, the timer may require an additional
oscillation to overflow.
Work around
Switching to the HFINTOSC after reloading, the
timer ensures the Timer1 will see a falling edge
before switching back to the external clock source.
Due to the time from Timer1 overflow to the reload
being application specific, wait for the timer to
increment before beginning the reload sequence.
This ensures the timer does not miss a rising edge
during reload.
© 2009 Microchip Technology Inc.