PIC16C74-10I/P Microchip Technology, PIC16C74-10I/P Datasheet - Page 40

• Manufacturer Part Number: PIC16C74-10I/P
• Description: MICRO CTRL 4K 10MHZ OTP ET 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C74-10I/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 10MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 6 V
• Data Converters: A/D 8x8b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Eeprom Size: -

PIC16C7X
4.3
The program counter (PC) is 13-bits wide. The low byte
comes from the PCL register, which is a readable and
writable register. The upper bits (PC<12:8>) are not
readable, but are indirectly writable through the
PCLATH register. On any reset, the upper bits of the
PC will be cleared. Figure 4-17 shows the two situa-
tions for the loading of the PC. The upper example in
the figure shows how the PC is loaded on a write to
PCL (PCLATH<4:0>
the figure shows how the PC is loaded during a CALL
or GOTO instruction (PCLATH<4:3>
FIGURE 4-17: LOADING OF PC IN
4.3.1
A computed GOTO is accomplished by adding an off-
set to the program counter (ADDWF PCL). When doing
a table read using a computed GOTO method, care
should be exercised if the table location crosses a PCL
memory boundary (each 256 byte block). Refer to the
application note “Implementing a Table Read" (AN556).
4.3.2
The PIC16CXX family has an 8 level deep x 13-bit wide
hardware stack. The stack space is not part of either
program or data space and the stack pointer is not
readable or writable. The PC is PUSHed onto the stack
when a CALL instruction is executed or an interrupt
causes a branch. The stack is POPed in the event of a
RETURN, RETLW or a RETFIE instruction execution.
PCLATH is not affected by a PUSH or POP operation.
The stack operates as a circular buffer. This means that
after the stack has been PUSHed eight times, the ninth
push overwrites the value that was stored from the first
push. The tenth push overwrites the second push (and
so on).
DS30390E-page 40
PC
PC
12
12 11 10
2
PCL and PCLATH
COMPUTED GOTO
STACK
Applicable Devices
72 73 73A 74 74A 76 77
PCH
5
PCLATH<4:3>
PCH
PCLATH
PCLATH<4:0>
8
PCLATH
8
DIFFERENT SITUATIONS
7
7
PCH). The lower example in
PCL
PCL
11
8
0
0
PCH).
Instruction with
PCL as
Destination
ALU
GOTO, CALL
Opcode <10:0>
4.4
PIC16C7X devices are capable of addressing a contin-
uous 8K word block of program memory. The CALL and
GOTO instructions provide only 11 bits of address to
allow branching within any 2K program memory page.
When doing a CALL or GOTO instruction the upper 2 bits
of the address are provided by PCLATH<4:3>. When
doing a CALL or GOTO instruction, the user must ensure
that the page select bits are programmed so that the
desired program memory page is addressed. If a return
from a CALL instruction (or interrupt) is executed, the
entire 13-bit PC is pushed onto the stack. Therefore,
manipulation of the PCLATH<4:3> bits are not required
for the return instructions (which POPs the address
from the stack).
Note:
Note 1: There are no status bits to indicate stack
Note 2: There are no instructions/mnemonics
Program Memory Paging
Applicable Devices
72 73 73A 74 74A 76 77
PIC16C7X devices with 4K or less of pro-
gram
PCLATH<4>. The use of PCLATH<4> as a
general purpose read/write bit is not rec-
ommended since this may affect upward
compatibility with future products.
overflow or stack underflow conditions.
called PUSH or POP. These are actions
that occur from the execution of the
CALL, RETURN, RETLW, and RETFIE
instructions, or the vectoring to an inter-
rupt address.
memory
1997 Microchip Technology Inc.
ignore
paging
bit