PIC16F636-I/P Microchip Technology Inc., PIC16F636-I/P Datasheet - Page 131

• Manufacturer Part Number: PIC16F636-I/P
• Description: 14 PIN, 3.5 KB FLASH, 128 RAM, 12 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16F636-I/P

• Comparators: 2
• Cpu Speed: 5 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 12
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 14-pin PDIP
• Programmable Memory: 3.5K Bytes
• Ram Size: 128 Bytes
• Speed: 20 MHz
• Timers: 1-8-bit, 1-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

12.15 In-Circuit Serial Programming
The PIC12F635/PIC16F636/639 microcontrollers can
be serially programmed while in the end application
circuit. This is simply done with two lines for clock and
data and three other lines for:
• Power
• Ground
• 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
firmware to be programmed.
The device is placed into a Program/Verify mode by hold-
ing the RA0 and RA1 pins low, while raising the MCLR
(V
Memory Programming Specification” (DS41204) for
more information. RA0 becomes the programming data
and RA1 becomes the programming clock. Both RA0
and RA1 are Schmitt Trigger inputs in this mode.
After Reset, to place the device into Program/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 supplied to or from the device, depending on
whether the command was a load or a read. For
complete details of serial programming, please refer to
the
Specification” (DS41204).
A typical In-Circuit Serial Programming connection is
shown in Figure 12-11.
FIGURE 12-11:
© 2005 Microchip Technology Inc.
PP
External
Connector
Signals
Data I/O
*Isolation devices (as required).
) pin from V
“PIC12F6XX/16F6XX
CLK
+5V
V
0V
PP
IL
to V
*
Connections
To Normal
To Normal
Connections
IHH
TYPICAL IN-CIRCUIT
SERIAL PROGRAMMING
CONNECTION
*
. See the “PIC12F6XX/16F6XX
*
*
Memory
V
V
MCLR/V
RA1
RA0
DD
SS
PIC16F636
Programming
PP
/RA3
PIC12F635/PIC16F636/639
Preliminary
12.16 In-Circuit Debugger
Since in-circuit debugging requires the loss of clock,
data and MCLR pins, MPLAB
a 14-pin device is not practical. A special 20-pin
PIC16F636 ICD device is used with MPLAB ICD 2 to
provide separate clock, data and MCLR pins and frees
all normally available pins to the user.
Use of the ICD device requires the purchase of a
MPLAB ICD 2 connector. On the bottom of the
header is a 14-pin socket that plugs into the user’s
target via the 14-pin stand-off connector.
When the ICD pin on the PIC16F636 ICD device is held
low, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB ICD 2. When the microcontroller has
this feature enabled, some of the resources are not
available for general use. Table 12-9 shows which
features are consumed by the background debugger:
TABLE 12-9:
For more information, see the “MPLAB
Circuit Debugger User’s Guide” (DS51331), available
on Microchip’s web site (www.microchip.com).
FIGURE 12-12:
special header. On the top of the header is an
I/O pins
Stack
Program Memory
Resource
20-Pin PDIP
ICDMCLR/V
In-Circuit Debug Device
RC5
RC4
RC3
RA5
RA4
RA3
V
ICD
NC
DD
PP
DEBUGGER RESOURCES
ICDCLK, ICDDATA
1 level
Address 0h must be NOP
700h-7FFh
20-PIN ICD PINOUT
10
1
2
3
4
5
6
7
8
9
®
ICD 2 development with
Description
20
19
18
17
16
15
14
13
12
11
DS41232B-page 129
ICDCLK
ICDDATA
V
RA0
RA1
RA2
RC0
RC1
RC2
ENPORT
SS
®
ICD 2 In-