PIC16F84A-20/SO Microchip Technology, PIC16F84A-20/SO Datasheet - Page 22

• Manufacturer Part Number: PIC16F84A-20/SO
• Description: IC MCU FLASH 1KX14 EE 18SOIC
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F84A-20/SO

• Core Size: 8-Bit
• Program Memory Size: 1.75KB (1K x 14)
• Core Processor: PIC
• Speed: 20MHz
• Peripherals: POR, WDT
• Number Of I /o: 13
• Program Memory Type: FLASH
• Eeprom Size: 64 x 8
• Ram Size: 68 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 18-SOIC (7.5mm Width)
• Controller Family/series: PIC16F
• No. Of I/o's: 13
• Eeprom Memory Size: 64Byte
• Ram Memory Size: 68Byte
• Cpu Speed: 20MHz
• No. Of Timers: 1
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 68 B
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 13
• Number Of Timers: 8
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: ICE2000
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: XLT18SO-1 - SOCKET TRANSITION 18SOIC 300MILI3-DB16F84A - BOARD DAUGHTER ICEPIC3309-1075 - ADAPTER 18-SOIC TO 18-SOIC309-1011 - ADAPTER 18-SOIC TO 18-DIP309-1010 - ADAPTER 18-SOIC TO 18-DIPAC164010 - MODULE SKT PROMATEII DIP/SOIC
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Details

PIC16F84A
5.2.1
The prescaler assignment is fully under software con-
trol (i.e., it can be changed “on the fly” during program
execution).
FIGURE 5-2:
TABLE 5-1:
DS35007B-page 20
01h
0Bh,8Bh
81h
85h
Legend: x = unknown, u = unchanged, - = unimplemented locations read as '0'. Shaded cells are not used by Timer0.
Address
Note:
Note: T0CS, T0SE, PSA, PS2:PS0 are (OPTION_REG<5:0>).
WDT Enable bit
RA4/T0CKI
Watchdog
CLKOUT (= F
Timer
pin
To avoid an unintended device RESET, a
specific instruction sequence (shown in the
PICmicro™ Mid-Range Reference Man-
ual, DS33023) must be executed when
changing the prescaler assignment from
Timer0 to the WDT. This sequence must
be followed even if the WDT is disabled.
SWITCHING PRESCALER
ASSIGNMENT
TMR0
INTCON
OPTION_REG
TRISA
Name
REGISTERS ASSOCIATED WITH TIMER0
OSC
T0SE
/4)
BLOCK DIAGRAM OF THE TIMER0/WDT PRESCALER
0
1
Timer0 Module Register
RBPU INTEDG
Bit 7
GIE
PSA
—
M
U
X
0
1
EEIE
Bit 6
T0CS
—
M
U
X
T0CS
Bit 5
T0IE
8-bit Prescaler
8 - to - 1 MUX
0
—
Time-out
8
M U X
WDT
PORTA Data Direction Register
T0SE
INTE
Bit 4
1
0
1
PSA
M
U
X
RBIE
Bit 3
PSA
5.3
The TMR0 interrupt is generated when the TMR0 reg-
ister overflows from FFh to 00h. This overflow sets bit
T0IF (INTCON<2>). The interrupt can be masked by
clearing bit T0IE (INTCON<5>). Bit T0IF must be
cleared in software by the Timer0 module Interrupt Ser-
vice Routine before re-enabling this interrupt. The
TMR0 interrupt cannot awaken the processor from
SLEEP since the timer is shut-off during SLEEP.
PSA
Bit 2
T0IF
PS2
PS2:PS0
Timer0 Interrupt
Cycles
SYNC
2
Bit 1
INTF
PS1
RBIF
Bit 0
PS0
2001 Microchip Technology Inc.
TMR0 reg
Data Bus
xxxx xxxx
0000 000x
1111 1111
---1 1111
Value on
POR,
BOR
8
Set Flag bit T0IF
on Overflow
Value on all
uuuu uuuu
0000 000u
1111 1111
---1 1111
RESETS
other