DM164120-2 Microchip Technology, DM164120-2 Datasheet - Page 22

• Manufacturer Part Number: DM164120-2
• Description: BOARD DEMO PICKIT 2 44PIN
• Manufacturer: Microchip Technology
• Type: MCUr

Specifications of DM164120-2

• Contents: 3 Boards (1 Populated, 2 Bare)
• Processor To Be Evaluated: PIC16F
• Silicon Manufacturer: Microchip
• Kit Contents: PIC16F Device, 2 PCB Boards
• Features: Small Surface Mount Prototype Area, Two Bare PCB Boards
• Development Tool Type: Hardware - Daughter Card
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: PIC16F887
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

44-Pin Demo Board User’s Guide
DS41296B-page 18
Rotate
The rotate instructions (RRF or RLF) shift all the bits in the file register right or left by
one position, through the Carry bit. The Carry bit is shifted into the byte and receives
the bit shifted out of the byte. The Carry bit should be cleared before rotation so
unwanted bits are not introduced into the display byte. The Carry bit also indicates
when the display byte is empty. When it is, reinsert the ‘1’ at bit 3.
PIC microcontrollers have two rotate instructions: Rotate Left (RLF) and Rotate Right
(RRF). These instructions rotate the contents of a file register and Carry bit one place.
The Carry bit is found in the STATUS Special Function Register.
FIGURE 3-2:
EXAMPLE 3-4:
Start:
MainLoop:
OndelayLoop:
BSF
CLRF
BCF
MOVLW
MOVWF
MOVF
MOVWF
DECFSZ
GOTO
DECFSZ
GOTO
BCF
RRF
BTFSC
BSF
GOTO
STATUS,RP0 ; select Register Bank 1
TRISD
STATUS,RP0 ; back to Register Bank 0
0x80
Display
Display,w
PORTD
Delay1,f
OndelayLoop
Delay2,f
OndelayLoop
STATUS,C
Display,f
STATUS,C
Display,7
MainLoop
ROTATE LEFT
ROTATE EXAMPLE
Carry
; make IO PortD all output
; Copy the display to the LEDs
; Delay .197 s
; ensure the carry bit is clear
; rotate display right
; Did the bit rotate into the carry?
; yes, put it into bit 7.
File Register
© 2007 Microchip Technology Inc.