PIC18LF6310-I/PT Microchip Technology, PIC18LF6310-I/PT Datasheet - Page 107

• Manufacturer Part Number: PIC18LF6310-I/PT
• Description: IC PIC MCU FLASH 4KX16 64TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 18Fr

Specifications of PIC18LF6310-I/PT

• Core Size: 8-Bit
• Program Memory Size: 8KB (4K x 16)
• Oscillator Type: Internal
• Core Processor: PIC
• Speed: 40MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, HLVD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Type: FLASH
• Ram Size: 768 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TFQFP
• Controller Family/series: PIC18
• No. Of I/o's: 54
• Ram Memory Size: 768Byte
• Cpu Speed: 40MHz
• No. Of Timers: 4
• No. Of Pwm: RoHS Compliant
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

9.0
9.1
All PIC18 devices include an 8 x 8 hardware multiplier
as part of the ALU. The multiplier performs an unsigned
operation and yields a 16-bit result that is stored in the
product register pair PRODH:PRODL. The multiplier’s
operation does not affect any flags in the STATUS
register.
Making multiplication a hardware operation allows it to
be completed in a single instruction cycle. This has the
advantages of higher computational throughput and
reduced code size for multiplication algorithms and
allows the PIC18 devices to be used in many applica-
tions previously reserved for digital signal processors.
A comparison of various hardware and software
multiply operations, along with the savings in memory
and execution time, is shown in
9.2
Example 9-1
8 x 8 unsigned multiplication. Only one instruction is
required when one of the arguments is already loaded
in the WREG register.
Example 9-2
multiplication. To account for the sign bits of the
arguments, each argument’s Most Significant bit (MSb)
is tested and the appropriate subtractions are done.
TABLE 9-1:
 2010 Microchip Technology Inc.
16 x 16 Unsigned
8 x 8 Unsigned
16 x 16 Signed
8 x 8 Signed
Routine
8 x 8 HARDWARE MULTIPLIER
Introduction
Operation
shows the sequence to do an 8 x 8 signed
shows the instruction sequence for an
PERFORMANCE COMPARISON FOR VARIOUS MULTIPLY OPERATIONS
Without Hardware Multiply
Without Hardware Multiply
Without Hardware Multiply
Without Hardware Multiply
Hardware Multiply
Hardware Multiply
Hardware Multiply
Hardware Multiply
Multiply Method
Table
9-1.
PIC18F6310/6410/8310/8410
Program
Memory
(Words)
13
33
21
28
52
35
1
6
EXAMPLE 9-1:
EXAMPLE 9-2:
MOVF
MULWF
MOVF
MULWF
BTFSC
SUBWF
MOVF
BTFSC
SUBWF
Cycles
(Max)
242
254
69
91
28
40
1
6
ARG1, W
ARG2
ARG1, W
ARG2
ARG2, SB
PRODH, F
ARG2, W
ARG1, SB
PRODH, F
@ 40 MHz
24.2 s
25.4 s
100 ns
600 ns
6.9 s
9.1 s
2.8 s
4.0 s
8 x 8 UNSIGNED
MULTIPLY ROUTINE
8 x 8 SIGNED MULTIPLY
ROUTINE
;
; ARG1 * ARG2 ->
; PRODH:PRODL
; ARG1 * ARG2 ->
; PRODH:PRODL
; Test Sign Bit
; PRODH = PRODH
;
; Test Sign Bit
; PRODH = PRODH
;
@ 10 MHz
102.6 s
27.6 s
36.4 s
96.8 s
16.0 s
11.2 s
Time
400 ns
2.4 s
DS39635C-page 107
- ARG1
- ARG2
@ 4 MHz
242 s
254 s
69 s
91 s
28 s
40 s
1 s
6 s