PIC16C505-04I/P Microchip Technology Inc., PIC16C505-04I/P Datasheet - Page 30

• Manufacturer Part Number: PIC16C505-04I/P
• Description: 14 PIN, 1.5 KB OTP, 72 RAM, 12 I/O
• Manufacturer: Microchip Technology Inc.

Specifications of PIC16C505-04I/P

• Cpu Speed: 5 MIPS
• Eeprom Memory: 0 Bytes
• Input Output: 11
• Memory Type: OTP
• Number Of Bits: 8
• Package Type: 14-pin PDIP
• Programmable Memory: 1.5K Bytes
• Ram Size: 72 Bytes
• Speed: 4 MHz
• Timers: 1- 8-bit
• Voltage, Range: 2-5.5 V
• Lead Free Status / Rohs Status: RoHS Compliant part Electrostatic Device

PIC16C505
7.2.5
The internal RC oscillator provides a fixed 4 MHz (nom-
inal) system clock at V
Specifications section for information on variation over
voltage and temperature.
In addition, a calibration instruction is programmed into
the last address of memory, which contains the calibra-
tion value for the internal RC oscillator. This location is
always protected, regardless of the code protect set-
tings. This value is programmed as a MOVLW
instruction where XX is the calibration value, and is
placed at the reset vector. This will load the W register
with the calibration value upon reset and the PC will
then roll over to the users program at address 0x000.
The user then has the option of writing the value to the
OSCCAL Register (05h) or ignoring it.
OSCCAL, when written to with the calibration value, will
“trim” the internal oscillator to remove process variation
from the oscillator frequency.
For the PIC16C505, only bits <7:2> of OSCCAL are
implemented.
7.3
The device differentiates between various kinds of
reset:
a) Power on reset (POR)
b) MCLR reset during normal operation
c) MCLR reset during SLEEP
d) WDT time-out reset during normal operation
e) WDT time-out reset during SLEEP
f) Wake-up from SLEEP on pin change
Some registers are not reset in any way, they are
unknown on POR and unchanged in any other reset.
Most other registers are reset to “reset state” on power-
on reset (POR), MCLR, WDT or wake-up on pin
change reset during normal operation. They are not
affected by a WDT reset during SLEEP or MCLR reset
during SLEEP, since these resets are viewed as
resumption of normal operation. The exceptions to this
are TO, PD and RBWUF bits. They are set or cleared
differently in different reset situations. These bits are
used in software to determine the nature of reset. See
Table 7-3 for a full description of reset states of all
registers.
DS40192C-page 30
Note:
INTERNAL 4 MHz RC OSCILLATOR
RESET
Please note that erasing the device will
also erase the pre-programmed internal
calibration value for the internal oscillator.
The calibration value must be read prior
to erasing the part so it can be repro-
grammed correctly later.
DD
= 5V and 25°C, see Electrical
XX
1999 Microchip Technology Inc.