PIC17C42A-16/P Microchip Technology, PIC17C42A-16/P Datasheet - Page 41

• Manufacturer Part Number: PIC17C42A-16/P
• Description: IC MCU OTP 2KX16 PWM 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 17Cr

Specifications of PIC17C42A-16/P

• Core Size: 8-Bit
• Program Memory Size: 4KB (2K x 16)
• Core Processor: PIC
• Speed: 16MHz
• Connectivity: UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Type: OTP
• Ram Size: 232 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Controller Family/series: PIC17
• No. Of I/o's: 33
• Ram Memory Size: 232Byte
• Cpu Speed: 16MHz
• No. Of Timers: 4
• No. Of Pwm Channels: 2
• Embedded Interface Type: USART
• Rohs Compliant: Yes
• Processor Series: PIC17C
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 232 B
• Interface Type: SCI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 33
• Number Of Timers: 4
• Maximum Operating Temperature: + 70 C
• Mounting Style: Through Hole
• Development Tools By Supplier: ICE2000
• Minimum Operating Temperature: 0 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: DVA17XP401 - DEVICE ADAPTER FOR PIC17C42AAC174001 - MODULE SKT PROMATEII 40DIP
• Eeprom Size: -
• Data Converters: -
• Lead Free Status / Rohs Status: Details

6.7
The Program Counter (PC) is a 16-bit register. PCL, the
low byte of the PC, is mapped in the data memory. PCL
is readable and writable just as is any other register.
PCH is the high byte of the PC and is not directly
addressable. Since PCH is not mapped in data or pro-
gram memory, an 8-bit register PCLATH (PC high latch)
is used as a holding latch for the high byte of the PC.
PCLATH is mapped into data memory. The user can
read or write PCH through PCLATH.
The 16-bit wide PC is incremented after each instruc-
tion fetch during Q1 unless:
• Modified by GOTO, CALL, LCALL, RETURN, RETLW,
• Modified by an interrupt response
• Due to destination write to PCL by an instruction
“Skips” are equivalent to a forced NOP cycle at the
skipped address.
Figure 6-11 and Figure 6-12 show the operation of the
program counter for various situations.
FIGURE 6-11: PROGRAM COUNTER
FIGURE 6-12: PROGRAM COUNTER USING
1996 Microchip Technology Inc.
or RETFIE instruction
Last write
to PCLATH
15
15
7
Program Counter Module
3
5 4
13
PCH
PCLATH
8
Internal data bus <8>
12
OPERATION
THE CALL AND GOTO
INSTRUCTIONS
PCLATH
PCH
5
8
8
8 7
8 7
0
Opcode
PCL
8
PCL
8
0
0
Using Figure 6-11, the operations of the PC and
PCLATH for different instructions are as follows:
a)
b)
c)
d)
e)
Using Figure 6-12, the operation of the PC and
PCLATH for GOTO and CALL instructions is a follows:
The read-modify-write only affects the PCL with the
result. PCH is loaded with the value in the PCLATH.
For example, ADDWF PCL will result in a jump within the
current page. If PC = 03F0h, WREG = 30h and
PCLATH = 03h before instruction, PC = 0320h after the
instruction. To accomplish a true 16-bit computed jump,
the user needs to compute the 16-bit destination
address, write the high byte to PCLATH and then write
the low value to PCL.
The following PC related operations do not change
PCLATH:
a)
b)
c)
LCALL instructions:
An 8-bit destination address is provided in the
instruction (opcode). PCLATH is unchanged.
PCLATH
Opcode<7:0>
Read instructions on PCL:
Any instruction that reads PCL.
PCL
PCH
Write instructions on PCL:
Any instruction that writes to PCL.
8-bit data
PCLATH
Read-Modify-Write instructions on PCL:
Any instruction that does a read-write-modify
operation on PCL, such as ADDWF PCL.
Read:
Write:
RETURN instruction:
PCH
Stack<MRU>
CALL, GOTO instructions:
A 13-bit destination address is provided in the
instruction (opcode).
Opcode<12:0>
PC<15:13>
Opcode<12:8>
LCALL, RETLW, and RETFIE instructions.
Interrupt vector is forced onto the PC.
Read-modify-write instructions on PCL (e.g. BSF
PCL).
data bus
PCLATH
PCLATH
PCL
8-bit result
PCLATH
PCH
PCH
data bus
PCLATH<7:5>
PC<15:0>
data bus
PCL
PC <12:0>
PCLATH <4:0>
ALU or destination
PCH
data bus
PIC17C4X
PCL
ALU
DS30412C-page 41
PCL