PIC18C858-E/L Microchip Technology, PIC18C858-E/L Datasheet - Page 71

• Manufacturer Part Number: PIC18C858-E/L
• Description: IC MCU OTP 16KX16 CAN 84PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 18Cr

Specifications of PIC18C858-E/L

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 40MHz
• Connectivity: CAN, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LVD, POR, PWM, WDT
• Number Of I /o: 68
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: OTP
• Ram Size: 1.5K x 8
• Voltage - Supply (vcc/vdd): 4.2 V ~ 5.5 V
• Data Converters: A/D 16x10b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 84-PLCC
• For Use With: AC164310 - MODULE SKT FOR PM3 84PLCCDVA18XL840 - ADAPTER DEVICE ICE 84PLCCAC174012 - MODULE SKT PROMATEII 84PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: PIC18C858E/L

6.0
An 8 x 8 hardware multiplier is included in the ALU of
the PIC18CXX8 devices. By making the multiply a
hardware operation, it completes in a single instruction
cycle. This is an unsigned multiply that gives a 16-bit
result. The result is stored into the 16-bit product regis-
ter pair (PRODH:PRODL). The multiplier does not
affect any flags in the STATUS register.
TABLE 6-1:
 2000 Microchip Technology Inc.
8 x 8 unsigned
8 x 8 signed
16 x 16 unsigned
16 x 16 signed
Routine
8 X 8 HARDWARE MULTIPLIER
PERFORMANCE COMPARISON
Without hardware multiply
Hardware multiply
Without hardware multiply
Hardware multiply
Without hardware multiply
Hardware multiply
Without hardware multiply
Hardware multiply
Multiply Method
Advanced Information
Program
Memory
(Words)
13
33
21
24
52
36
1
6
Making the 8 x 8 multiplier execute in a single cycle
gives the following advantages:
• Higher computational throughput
• Reduces code size requirements for multiply algo-
The performance increase allows the device to be used
in applications previously reserved for Digital Signal
Processors.
Table 6-1 shows a performance comparison between
enhanced devices using the single cycle hardware mul-
tiply, and performing the same function without the
hardware multiply.
rithms
Cycles
(Max)
242
254
69
91
24
36
1
6
@ 40 MHz
24.2 µs
25.4 µs
100 ns
600 ns
6.9 µs
9.1 µs
2.4 µs
3.6 µs
PIC18CXX8
@ 10 MHz
102.6 µs
27.6 µs
36.4 µs
96.8 µs
14.4 µs
Time
400 ns
2.4 µs
9.6 µs
DS30475A-page 71
@ 4 MHz
242 µs
254 µs
69 µs
91 µs
24 µs
36 µs
1 µs
6 µs