PIC16F690-E/ML Microchip Technology, PIC16F690-E/ML Datasheet - Page 93

• Manufacturer Part Number: PIC16F690-E/ML
• Description: IC, 8BIT MCU, PIC16F, 20MHZ, QFN-20
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F690-E/ML

• Controller Family/series: PIC16F
• No. Of I/o's: 18
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 256Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• Core Size: 8 Bit
• Program Memory Size: 4096 Words
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 18
• 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 12x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 20-VQFN Exposed Pad, 20-HVQFN, 20-SQFN, 20-DHVQFN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT20QFN-1 - SOCKET TRANSITION 20DIP-20QFNAC164324 - MODULE SKT FOR MPLAB 8DFN/16QFNPIC16F690DM-PCTLHS - BOARD DEMO PICTAIL HUMIDITY SNSRAC162061 - HEADER INTRFC MPLAB ICD2 20PIN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

7.0
The Timer2 module is an eight-bit timer with the
following features:
• 8-bit timer register (TMR2)
• 8-bit period register (PR2)
• Interrupt on TMR2 match with PR2
• Software programmable prescaler (1:1, 1:4, 1:16)
• Software programmable postscaler (1:1 to 1:16)
See Figure 7-1 for a block diagram of Timer2.
7.1
The clock input to the Timer2 module is the system
instruction clock (F
Timer2 prescaler, which has prescale options of 1:1,
1:4 or 1:16. The output of the prescaler is then used to
increment the TMR2 register.
The values of TMR2 and PR2 are constantly compared
to determine when they match. TMR2 will increment
from 00h until it matches the value in PR2. When a
match occurs, two things happen:
• TMR2 is reset to 00h on the next increment cycle.
• The Timer2 postscaler is incremented
The match output of the Timer2/PR2 comparator is fed
into the Timer2 postscaler. The postscaler has
postscale options of 1:1 to 1:16 inclusive. The output of
the Timer2 postscaler is used to set the TMR2IF
interrupt flag bit in the PIR1 register.
FIGURE 7-1:
© 2008 Microchip Technology Inc.
TIMER2 MODULE
Timer2 Operation
F
OSC
/4
OSC
TIMER2 BLOCK DIAGRAM
/4). The clock is fed into the
T2CKPS<1:0>
1:1, 1:4, 1:16
Prescaler
PIC16F631/677/685/687/689/690
2
Comparator
TMR2
PR2
EQ
Reset
The TMR2 and PR2 registers are both fully readable
and writable. On any Reset, the TMR2 register is set to
00h and the PR2 register is set to FFh.
Timer2 is turned on by setting the TMR2ON bit in the
T2CON register to a ‘1’. Timer2 is turned off by clearing
the TMR2ON bit to a ‘0’.
The Timer2 prescaler is controlled by the T2CKPS bits
in the T2CON register. The Timer2 postscaler is
controlled by the TOUTPS bits in the T2CON register.
The prescaler and postscaler counters are cleared
when:
• A write to TMR2 occurs.
• A write to T2CON occurs.
• Any device Reset occurs (Power-on Reset, MCLR
Reset, Watchdog Timer Reset or Brown-out
Reset).
Note:
TOUTPS<3:0>
Postscaler
1:1 to 1:16
Output
TMR2
TMR2 is not cleared when T2CON is
written.
4
Sets Flag
bit TMR2IF
DS41262E-page 91