PIC18F2539-I/SP Microchip Technology, PIC18F2539-I/SP Datasheet - Page 70

• Manufacturer Part Number: PIC18F2539-I/SP
• Description: IC MCU FLASH 12KX16 EE A/D 28DIP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18F2539-I/SP

• Core Size: 8-Bit
• Program Memory Size: 24KB (12K x 16)
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 21
• Program Memory Type: FLASH
• Eeprom Size: 256 x 8
• Ram Size: 1408 x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 5x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-DIP (0.300", 7.62mm)
• Controller Family/series: PIC18
• No. Of I/o's: 21
• Eeprom Memory Size: 256Byte
• Ram Memory Size: 1.375KB
• Cpu Speed: 40MHz
• No. Of Timers: 4
• Processor Series: PIC18F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 1408 B
• Interface Type: I2C, SPI, AUSART
• Maximum Clock Frequency: 40 MHz
• Number Of Programmable I/os: 21
• Number Of Timers: 3
• Operating Supply Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734, 52712-325, EWPIC18
• Development Tools By Supplier: DV164005, DV164136
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 5 Channel
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With: DVA18XP280 - DEVICE ADAPTER 18F2220 PDIP 28LD
• Lead Free Status / Rohs Status: Details

PIC18FXX39
Example 7-3 shows the sequence to do a 16 x 16
unsigned multiply. Equation 7-1 shows the algorithm
that is used. The 32-bit result is stored in four registers,
RES3:RES0.
EQUATION 7-1:
EXAMPLE 7-3:
Example 7-4 shows the sequence to do a 16 x 16
signed multiply. Equation 7-2 shows the algorithm
used. The 32-bit result is stored in four registers,
RES3:RES0. To account for the sign bits of the argu-
ments, each argument pairs Most Significant bit (MSb)
is tested and the appropriate subtractions are done.
DS30485A-page 68
;
;
;
RES3:RES0
MOVF
MULWF
MOVFF
MOVFF
MOVF
MULWF
MOVFF
MOVFF
MOVF
MULWF
MOVF
ADDWF
MOVF
ADDWFC RES2,
CLRF
ADDWFC RES3,
MOVF
MULWF
MOVF
ADDWF
MOVF
ADDWFC RES2,
CLRF
ADDWFC RES3,
ARG1L, W
ARG2L
PRODH, RES1 ;
PRODL, RES0 ;
ARG1H, W
ARG2H
PRODH, RES3 ;
PRODL, RES2 ;
ARG1L, W
ARG2H
PRODL, W
RES1,
PRODH, W
WREG
ARG1H, W
ARG2L
PRODL, W
RES1,
PRODH, W
WREG
=
=
ARG1H:ARG1L • ARG2H:ARG2L
(ARG1H • ARG2H • 2
(ARG1H • ARG2L • 2
(ARG1L • ARG2H • 2
(ARG1L • ARG2L)
16 x 16 UNSIGNED
MULTIPLICATION
ALGORITHM
16 x 16 UNSIGNED
MULTIPLY ROUTINE
F
F
F
F
F
F
; ARG1L * ARG2L ->
; PRODH:PRODL
; ARG1H * ARG2H ->
; PRODH:PRODL
; ARG1L * ARG2H ->
; PRODH:PRODL
;
; Add cross
; products
;
;
;
;
; ARG1H * ARG2L ->
; PRODH:PRODL
;
; Add cross
; products
;
;
;
8
8
16
) +
) +
) +
Preliminary
EQUATION 7-2:
EXAMPLE 7-4:
;
;
;
;
;
SIGN_ARG1
;
CONT_CODE
RES3:RES0
MOVF
MULWF
MOVFF
MOVFF
MOVF
MULWF
MOVFF
MOVFF
MOVF
MULWF
MOVF
ADDWF
MOVF
ADDWFC RES2,
CLRF
ADDWFC RES3,
MOVF
MULWF
MOVF
ADDWF
MOVF
ADDWFC RES2,
CLRF
ADDWFC RES3,
BTFSS
BRA
MOVF
SUBWF
MOVF
SUBWFB RES3
BTFSS
BRA
MOVF
SUBWF
MOVF
SUBWFB RES3
=
=
:
ARG1H:ARG1L • ARG2H:ARG2L
(ARG1H • ARG2H • 2
(ARG1H • ARG2L • 2
(ARG1L • ARG2H • 2
(ARG1L • ARG2L) +
(-1 • ARG2H<7> • ARG1H:ARG1L • 2
(-1 • ARG1H<7> • ARG2H:ARG2L • 2
ARG1L, W
ARG2L
PRODH, RES1 ;
PRODL, RES0 ;
ARG1H, W
ARG2H
PRODH, RES3 ;
PRODL, RES2 ;
ARG1L, W
ARG2H
PRODL, W
RES1,
PRODH, W
WREG
ARG1H, W
ARG2L
PRODL, W
RES1,
PRODH, W
WREG
ARG2H, 7
SIGN_ARG1
ARG1L, W
RES2
ARG1H, W
ARG1H, 7
CONT_CODE
ARG2L, W
RES2
ARG2H, W
16 x 16 SIGNED
MULTIPLICATION
ALGORITHM
16 x 16 SIGNED
MULTIPLY ROUTINE
F
F
F
F
F
F
 2002 Microchip Technology Inc.
; ARG1L * ARG2L ->
; PRODH:PRODL
; ARG1H * ARG2H ->
; PRODH:PRODL
; ARG1L * ARG2H ->
; PRODH:PRODL
;
; Add cross
; products
;
;
;
;
; ARG1H * ARG2L ->
; PRODH:PRODL
;
; Add cross
; products
;
;
;
; ARG2H:ARG2L neg?
; no, check ARG1
;
;
;
; ARG1H:ARG1L neg?
; no, done
;
;
;
8
8
16
) +
) +
) +
16
16
) +
)