PIC16C554-20I/P Microchip Technology, PIC16C554-20I/P Datasheet - Page 53

• Manufacturer Part Number: PIC16C554-20I/P
• Description: IC MCU OTP 512X14 18DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C554-20I/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: POR, WDT
• Number Of I /o: 13
• Program Memory Size: 896B (512 x 14)
• Program Memory Type: OTP
• Ram Size: 80 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 18-DIP (0.300", 7.62mm)
• Processor Series: PIC16C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 80 B
• Maximum Clock Frequency: 20 MHz
• Number Of Programmable I/os: 13
• Number Of Timers: 8
• Operating Supply Voltage: 2.5 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: ICE2000
• Minimum Operating Temperature: - 40 C
• Data Rom Size: 80 B
• Height: 3.3 mm
• Length: 22.86 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Width: 6.35 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -
• Lead Free Status / Rohs Status: Details

7.3.1
The prescaler assignment is fully under software
control (i.e., it can be changed “on the fly” during
program execution). To avoid an unintended device
RESET,
(Example 7-1) must be executed when changing the
prescaler assignment from Timer0 to WDT. Lines 5-7
are required only if the desired postscaler rate is 1:1
(PS<2:0> = 000) or 1:2 (PS<2:0> = 001).
EXAMPLE 7-1:
TABLE 7-1:
 2002 Microchip Technology Inc.
01h
0Bh/8Bh
81h
85h
Legend:
Note
Address
BCF
CLRF
BSF
MOVLW '00101111’b ;These 3 lines (5, 6, 7)
MOVWF OPTION
MOVLW '00101xxx’b ;Set Postscaler to
MOVWF OPTION
BCF
1:
TMR0
INTCON
OPTION
TRISA
STATUS, RP0 ;Skip if already in
TMR0
STATUS, RP0 ;Bank 1
STATUS, RP0 ;Return to Bank 0
— = Unimplemented locations, read as ‘0’,
Shaded bits are not used by TMR0 module.
Name
the
SWITCHING PRESCALER
ASSIGNMENT
REGISTERS ASSOCIATED WITH TIMER0
following
Timer0 module’s register
RBPU
Bit 7
GIE
—
CHANGING PRESCALER
(TIMER0→WDT)
;Bank 0 CLRWDT Clear WDT
;Clear TMR0 & Prescaler
;Are required only if
;Desired PS<2:0> are
;CLRWDT 000 or 001
;Desired WDT rate
Reserved
INTEDG
Bit 6
instruction
—
T0CS
Bit 5
T0IE
—
sequence
TRISA4
T0SE
INTE
Bit 4
Preliminary
TRISA3
RBIE
Bit 3
PSA
To change prescaler from the WDT to the TMR0
module use the sequence shown in Example 7-2. This
precaution must be taken even if the WDT is disabled.
EXAMPLE 7-2:
TRISA2
Bit 2
T0IF
PS2
CLRWDT
BSF
MOVLW
MOVWF
BCF
TRISA1
INTF
Bit 1
PS1
STATUS, RP0
b'xxxx0xxx' ;Select TMR0, new
OPTION
STATUS, RP0
TRISA0
RBIF
Bit 0
PS0
CHANGING PRESCALER
(WDT→TIMER0)
PIC16C55X
;Clear WDT and
;prescaler
;prescale value and
;clock source
xxxx xxxx
0000 000x
1111 1111
---1 1111
Value on
POR
DS40143D-page 51
uuuu uuuu
0000 000x
1111 1111
---1 1111
Value on
All Other
RESETS