PIC16C770-I/P Microchip Technology, PIC16C770-I/P Datasheet - Page 47

• Manufacturer Part Number: PIC16C770-I/P
• Description: IC MCU CMOS A/D 2K 20MHZ 20-DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C770-I/P

• Core Size: 8-Bit
• Program Memory Size: 3.5KB (2K x 14)
• Oscillator Type: Internal
• Core Processor: PIC
• Speed: 20MHz
• Connectivity: I²C, SPI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 15
• Program Memory Type: OTP
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 6x12b
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 20-DIP (0.300", 7.62mm)
• Controller Family/series: PIC16C
• No. Of I/o's: 16
• Ram Memory Size: 256Byte
• Cpu Speed: 20MHz
• No. Of Timers: 3
• No. Of: RoHS Compliant
• Core: PIC
• Processor Series: PIC16C
• Data Bus Width: 8 bit
• Maximum Clock Frequency: 20 MHz
• Data Ram Size: 256 B
• Data Rom Size: 256 B
• On-chip Adc: 6 bit
• Number Of Programmable I/os: 16
• Number Of Timers: 3 bit
• Operating Supply Voltage: 2.5 V to 5.5 V
• Mounting Style: Through Hole
• Height: 3.3 mm
• Interface Type: I2C, SPI, SSP
• Length: 26.16 mm
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 4 V
• Width: 6.35 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: DVA16XP200 - ADAPTER ICE 20DIP/SOIC/SSOPAC164028 - MODULE SKT PROMATEII 20SOIC/DIP
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details
• Other names: PIC16C770I/P

5.0
The Timer0 module timer/counter has the following fea-
tures:
• 8-bit timer/counter
• Readable and writable
• Internal or external clock select
• Edge select for external clock
• 8-bit software programmable prescaler
• Interrupt on overflow from FFh to 00h
Figure 5-1 is a simplified block diagram of the Timer0
module.
Additional information on timer modules is available in
the PICmicro™ Mid-Range MCU Family Reference
Manual, (DS33023).
5.1
Timer0 can operate as a timer or as a counter.
Timer mode is selected by clearing bit T0CS
(OPTION_REG<5>). In Timer mode, the Timer0 mod-
ule will increment every instruction cycle (without pres-
caler). If the TMR0 register is written, the increment is
inhibited for the following two instruction cycles. The
user can work around this by writing an adjusted value
to the TMR0 register.
Counter mode is selected by setting bit T0CS
(OPTION_REG<5>). In Counter mode, Timer0 will
increment either on every rising or falling edge of pin
RA4/T0CKI. The incrementing edge is determined by
the
(OPTION_REG<4>). Clearing bit T0SE selects the ris-
ing edge. Restrictions on the external clock input are
discussed in below.
When an external clock input is used for Timer0, it must
meet certain requirements. The requirements ensure
the external clock can be synchronized with the internal
phase clock (T
incrementing of Timer0 after synchronization.
FIGURE 5-1:
2002 Microchip Technology Inc.
RA4/T0CKI
pin
Note 1: T0CS, T0SE, PSA, PS<2:0> (OPTION_REG<5:0>).
Timer0
TIMER0 MODULE
Timer0 Operation
2: The prescaler is shared with Watchdog Timer (refer to Figure 5-2 for detailed block diagram).
OSC
T0SE
Source
TIMER0 BLOCK DIAGRAM
Fosc/4
). Also, there is a delay in the actual
Edge
T0CS
0
1
Select
PS2, PS1, PS0
Programmable
bit
Prescaler
T0SE
3
PSA
1
0
Additional information on external clock requirements
is available in the PICmicro™ Mid-Range MCU Family
Reference Manual, (DS33023).
5.2
An 8-bit counter is available as a prescaler for the
Timer0 module, or as a postscaler for the Watchdog
Timer, respectively (Figure 5-2). 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 prescaler is not readable or writable.
The PSA and PS<2:0> bits (OPTION_REG<3:0>)
determine the prescaler assignment and prescale ratio.
Clearing bit PSA will assign the prescaler to the Timer0
module. When the prescaler is assigned to the Timer0
module, prescale values of 1:2, 1:4, ..., 1:256 are
selectable.
Setting bit PSA will assign the prescaler to the Watch-
dog Timer (WDT). When the prescaler is assigned to
the WDT, prescale values of 1:1, 1:2, ..., 1:128 are
selectable.
When assigned to the Timer0 module, all instructions
writing to the TMR0 register (e.g. CLRF 1, MOVWF 1,
BSF 1, x....etc.) will clear the prescaler. When
assigned to WDT, a CLRWDT instruction will clear the
prescaler along with the WDT.
PSout
Note:
PIC16C717/770/771
(2 Tcy delay)
Sync with
Prescaler
Internal
clocks
Writing to TMR0 when the prescaler is
assigned to Timer0 will clear the prescaler
count, but will not change the prescaler
assignment.
PSout
Data Bus
TMR0
8
DS41120B-page 45
Set interrupt
flag bit T0IF
on overflow