PIC17LC756A-08/L Microchip Technology, PIC17LC756A-08/L Datasheet - Page 69

• Manufacturer Part Number: PIC17LC756A-08/L
• Description: IC MCU OTP 16KX16 A/D 68PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 17Cr

Specifications of PIC17LC756A-08/L

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 50
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: OTP
• Ram Size: 902 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 68-PLCC
• Processor Series: PIC17LC
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 902 B
• Interface Type: I2C, MSSP, RS- 232, SCI, SPI, USART
• Maximum Clock Frequency: 8 MHz
• Number Of Programmable I/os: 50
• Number Of Timers: 8
• Operating Supply Voltage: 3 V to 5.5 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: 0 C
• On-chip Adc: 12 bit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

Example 9-4 shows the sequence to do a 16 x 16
signed multiply. Equation 9-2 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.
EQUATION 9-2:
RES3:RES0
2000 Microchip Technology Inc.
= 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
16 x 16 SIGNED
MULTIPLICATION
ALGORITHM
8
8
16
)
)
)
16
16
)
)
+
+
+
+
+
EXAMPLE 9-4:
;
;
;
;
;
SIGN_ARG1
;
CONT_CODE
MOVFP
MULWF
MOVPF
MOVPF
MOVFP
MULWF
MOVPF
MOVPF
MOVFP
MULWF
MOVFP
ADDWF
MOVFP
ADDWFC
CLRF
ADDWFC
MOVFP
MULWF
MOVFP
ADDWF
MOVFP
ADDWFC
CLRF
ADDWFC
BTFSS
GOTO
MOVFP
SUBWF
MOVFP
SUBWFB
BTFSS
GOTO
MOVFP
SUBWF
MOVFP
SUBWFB
:
ARG1L, WREG
ARG2L
PRODH, RES1 ;
PRODL, RES0 ;
ARG1H, WREG
ARG2H
PRODH, RES3 ;
PRODL, RES2 ;
ARG1L, WREG
ARG2H
PRODL, WREG ;
RES1, F
PRODH, WREG ;
RES2, F
WREG, F
RES3, F
ARG1H, WREG ;
ARG2L
PRODL, WREG ;
RES1, F
PRODH, WREG ;
RES2, F
WREG, F
RES3, F
ARG2H, 7
SIGN_ARG1
ARG1L, WREG ;
RES2
ARG1H, WREG ;
RES3
ARG1H, 7
CONT_CODE
ARG2L, WREG ;
RES2
ARG2H, WREG ;
RES3
16 x 16 SIGNED
MULTIPLY ROUTINE
PIC17C7XX
; ARG1L * ARG2L ->
;
; ARG1H * ARG2H ->
;
; ARG1L * ARG2H ->
;
; Add cross
;
;
;
; ARG1H * ARG2L ->
;
; Add cross
;
;
;
; ARG2H:ARG2L neg?
; no, check ARG1
;
; ARG1H:ARG1L neg?
; no, done
;
PRODH:PRODL
PRODH:PRODL
PRODH:PRODL
PRODH:PRODL
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DS30289B-page 69