PIC16C74-04/P Microchip Technology, PIC16C74-04/P Datasheet - Page 146

• Manufacturer Part Number: PIC16C74-04/P
• Description: MICRO CTRL 4K 4MHZ OTP 40DIP
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C74-04/P

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 4MHz
• 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: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Request inventory verification / Request inventory verification
• Eeprom Size: -

PIC16C7X
FIGURE 14-20: WAKE-UP FROM SLEEP THROUGH INTERRUPT
14.9
If the code protection bit(s) have not been pro-
grammed, the on-chip program memory can be read
out for verification purposes.
14.10
Four memory locations (2000h - 2003h) are designated
as ID locations where the user can store checksum or
other code-identification numbers. These locations are
not accessible during normal execution but are read-
able and writable during program/verify. It is recom-
mended that only the 4 least significant bits of the ID
location are used.
14.11
PIC16CXX microcontrollers can be serially pro-
grammed while in the end application circuit. This is
simply done with two lines for clock and data, and three
other lines for power, ground, and the programming
voltage. This allows customers to manufacture boards
with unprogrammed devices, and then program the
microcontroller just before shipping the product. This
also allows the most recent firmware or a custom firm-
ware to be programmed.
DS30390E-page 146
Note 1:
Note:
INSTRUCTION FLOW
INTF flag
(INTCON<1>)
GIE bit
(INTCON<7>)
Instruction
fetched
Instruction
executed
CLKOUT(4)
2:
3:
4:
INT pin
OSC1
Program Verification/Code Protection
ID Locations
Applicable Devices
72 73 73A 74 74A 76 77
Applicable Devices
72 73 73A 74 74A 76 77
Applicable Devices
72 73 73A 74 74A 76 77
PC
In-Circuit Serial Programming
XT, HS or LP oscillator mode assumed.
T
GIE = '1' assumed. In this case after wake- up, the processor jumps to the interrupt routine. If GIE = '0', execution will continue in-line.
CLKOUT is not available in these osc modes, but shown here for timing reference.
Microchip does not recommend code pro-
tecting windowed devices.
OST
Inst(PC) = SLEEP
Q1 Q2 Q3 Q4
= 1024T
Inst(PC - 1)
PC
OSC
(drawing not to scale) This delay will not be there for RC osc mode.
Q1 Q2 Q3 Q4
Inst(PC + 1)
SLEEP
PC+1
Q1
Processor in
SLEEP
PC+2
T
OST
(2)
Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4
Inst(PC + 2)
Inst(PC + 1)
The device is placed into a program/verify mode by
holding the RB6 and RB7 pins low while raising the
MCLR (V
specification). RB6 becomes the programming clock
and RB7 becomes the programming data. Both RB6
and RB7 are Schmitt Trigger inputs in this mode.
After reset, to place the device into programming/verify
mode, the program counter (PC) is at location 00h. A 6-
bit command is then supplied to the device. Depending
on the command, 14-bits of program data are then sup-
plied to or from the device, depending if the command
was a load or a read. For complete details of serial pro-
gramming, please refer to the PIC16C6X/7X Program-
ming Specifications (Literature #DS30228).
FIGURE 14-21: TYPICAL IN-CIRCUIT SERIAL
PC+2
External
Connector
Signals
Data I/O
CLK
+5V
V
0V
PP
PP
Interrupt Latency
Dummy cycle
) pin from V
(Note 2)
PC + 2
PROGRAMMING
CONNECTION
To Normal
Connections
To Normal
Connections
Q1 Q2 Q3 Q4
IL
1997 Microchip Technology Inc.
Inst(0004h)
Dummy cycle
to V
0004h
IHH
(see programming
V
V
MCLR/V
RB6
RB7
Q1 Q2 Q3 Q4
DD
SS
PIC16CXX
Inst(0005h)
Inst(0004h)
0005h
V
PP
DD