PIC17C43-25I/PT Microchip Technology, PIC17C43-25I/PT Datasheet - Page 29

• Manufacturer Part Number: PIC17C43-25I/PT
• Description: IC MCU OTP 4KX16 PWM 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 17Cr

Specifications of PIC17C43-25I/PT

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: UART/USART
• Peripherals: POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: OTP
• Ram Size: 454 x 8
• Voltage - Supply (vcc/vdd): 4.5 V ~ 6 V
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• For Use With: AC164315 - MODULE SKT MPLAB PM3 44TQFP309-1008 - ADAPTER 44-TQFP TO 40-DIPAC174005 - MODULE SKT PROMATEII 44TQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

6.0
There are two memory blocks in the PIC17C4X; pro-
gram memory and data memory. Each block has its
own bus, so that access to each block can occur during
the same oscillator cycle.
The data memory can further be broken down into Gen-
eral Purpose RAM and the Special Function Registers
(SFRs). The operation of the SFRs that control the
“core” are described here. The SFRs used to control
the peripheral modules are described in the section dis-
cussing each individual peripheral module.
6.1
PIC17C4X devices have a 16-bit program counter
capable of addressing a 64K x 16 program memory
space. The reset vector is at 0000h and the interrupt
vectors are at 0008h, 0010h, 0018h, and 0020h
(Figure 6-1).
6.1.1
The PIC17C4X can operate in one of four possible pro-
gram memory configurations. The configuration is
selected by two configuration bits. The possible modes
are:
• Microprocessor
• Microcontroller
• Extended Microcontroller
• Protected Microcontroller
The microcontroller and protected microcontroller
modes only allow internal execution. Any access
beyond the program memory reads unknown data.
The protected microcontroller mode also enables the
code protection feature.
The extended microcontroller mode accesses both the
internal program memory as well as external program
memory. Execution automatically switches between
internal and external memory. The 16-bits of address
allow a program memory range of 64K-words.
The microprocessor mode only accesses the external
program memory. The on-chip program memory is
ignored. The 16-bits of address allow a program mem-
ory range of 64K-words. Microprocessor mode is the
default mode of an unprogrammed device.
The different modes allow different access to the con-
figuration bits, test memory, and boot ROM. Table 6-1
lists which modes can access which areas in memory.
Test Memory and Boot Memory are not required for
normal operation of the device. Care should be taken to
ensure that no unintended branches occur to these
areas.
1996 Microchip Technology Inc.
MEMORY ORGANIZATION
Program Memory Organization
PROGRAM MEMORY OPERATION
This document was created with FrameMaker 4 0 4
FIGURE 6-1:
Note 1:
CALL, RETURN
RETFIE, RETLW
2: This location is reserved on the PIC17C42.
User memory space may be internal, external, or
both. The memory configuration depends on the
processor mode.
T0CKI Pin Interrupt Vector
Peripheral Interrupt Vector
INT Pin Interrupt Vector
Timer0 Interrupt Vector
PROGRAM MEMORY MAP
AND STACK
Stack Level 16
Stack Level 1
Reset Vector
Test EPROM
PC<15:0>
Boot ROM
Reserved
Reserved
Reserved
WDTPS0
WDTPS1
FOSC0
FOSC1
PM2
PM0
PM1
(2)
PIC17C4X
16
DS30412C-page 29
FDFFh
FE00h
FE01h
FE02h
FE03h
FE04h
FE05h
FE06h
FE07h
FE08h
FE0Eh
FE0Fh
FE10h
FF5Fh
FF60h
FFFFh
(PIC17C42,
0000h
0008h
0010h
0018h
0020h
0021h
7FFh
FFFh
(PIC17C43
1FFFh
(PIC17C44)
PIC17CR42,
PIC17C42A)
PIC17CR43)