PIC18F4520-I/P Microchip Technology Inc., PIC18F4520-I/P Datasheet - Page 268

• Manufacturer Part Number: PIC18F4520-I/P
• Description: 40 Pin, 32 KB Flash, 1536 RAM, 36 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC18F4520-I/P

• A/d Inputs: 13-Channel, 10-Bit
• Comparators: 2
• Cpu Speed: 10 MIPS
• Eeprom Memory: 256 Bytes
• Input Output: 36
• Interface: I2C/SPI/USART
• Memory Type: Flash
• Number Of Bits: 8
• Package Type: 40-pin PDIP
• Programmable Memory: 32K Bytes
• Ram Size: 1.5K Bytes
• Speed: 40 MHz
• Timers: 1-8-bit, 3-16-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC18F2420/2520/4420/4520
23.5.2
The entire data EEPROM is protected from external
reads and writes by two bits: CPD and WRTD. CPD
inhibits external reads and writes of data EEPROM.
WRTD inhibits internal and external writes to data
EEPROM. The CPU can always read data EEPROM
under normal operation, regardless of the protection bit
settings.
23.5.3
The configuration registers can be write-protected. The
WRTC bit controls protection of the configuration
registers. In normal execution mode, the WRTC bit is
readable only. WRTC can only be written via ICSP or
an external programmer.
23.6
Eight memory locations (200000h-200007h) are
designated as ID locations, where the user can store
checksum or other code identification numbers. These
locations are both readable and writable during normal
execution through the TBLRD and TBLWT instructions
or during program/verify. The ID locations can be read
when the device is code-protected.
23.7
PIC18F2420/2520/4420/4520 devices 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 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
firmware to be programmed.
23.8
When the DEBUG configuration bit is programmed to a
‘0’, the In-Circuit Debugger functionality is enabled.
This function allows simple debugging functions when
used with MPLAB
this feature enabled, some resources are not available
for general use. Table 23-4 shows which resources are
required by the background debugger.
TABLE 23-4:
DS39631A-page 266
I/O pins:
Stack:
Program Memory:
Data Memory:
ID Locations
In-Circuit Debugger
In-Circuit Serial Programming
DATA EEPROM
CODE PROTECTION
CONFIGURATION REGISTER
PROTECTION
®
DEBUGGER RESOURCES
IDE. When the microcontroller has
RB6, RB7
2 levels
512 bytes
10 bytes
Preliminary
To use the In-Circuit Debugger function of the micro-
controller, the design must implement In-Circuit Serial
Programming connections to MCLR/V
V
Debugger module available from Microchip or one of
the third party development tool companies.
23.9
The LVP configuration bit enables Single-Supply ICSP
Programming (formerly known as Low-Voltage ICSP
Programming or LVP). When Single-Supply Program-
ming is enabled, the microcontroller can be programmed
without requiring high voltage being applied to the
MCLR/V
dedicated to controlling Program mode entry and is not
available as a general purpose I/O pin.
While programming, using Single-Supply Programming
mode, V
normal execution mode. To enter Programming mode,
V
If Single-Supply ICSP Programming mode will not be
used, the LVP bit can be cleared. RB5/KBI1/PGM then
becomes available as the digital I/O pin, RB5. The LVP
bit may be set or cleared only when using standard
high-voltage programming (V
V
standard high-voltage programming is available and
must be used to program the device.
Memory that is not code-protected can be erased using
either a block erase, or erased row by row, then written
at any specified V
erased, a block erase is required. If a block erase is to
be performed when using Low-Voltage Programming,
the device must be supplied with V
SS
DD
PP
Note 1: High-voltage programming is always
, RB7 and RB6. This will interface to the In-Circuit
/RE3 pin). Once LVP has been disabled, only the
is applied to the PGM pin.
PP
DD
2: By
3: When Single-Supply Programming is
4: When LVP is enabled, externally pull the
Single-Supply ICSP Programming
/RE3 pin, but the RB5/KBI1/PGM pin is then
is applied to the MCLR/V
available, regardless of the state of the
LVP bit or the PGM pin, by applying V
to the MCLR pin.
enabled in unprogrammed devices (as
supplied from Microchip) and erased
devices.
enabled, the RB5 pin can no longer be
used as a general purpose I/O pin.
PGM pin to V
execution.
DD
default,
. If code-protected memory is to be
 2004 Microchip Technology Inc.
SS
Single-Supply
to allow normal program
IHH
applied to the MCLR/
DD
PP
of 4.5V to 5.5V.
/RE3 pin as in
PP
/RE3, V
ICSP
IHH
DD
is
,