PIC16C774-E/L Microchip Technology, PIC16C774-E/L Datasheet - Page 30

• Manufacturer Part Number: PIC16C774-E/L
• Description: IC MCU OTP 4KX14 A/D PWM 44PLCC
• Manufacturer: Microchip Technology
• Series: PIC® 16Cr

Specifications of PIC16C774-E/L

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 33
• Program Memory Size: 7KB (4K x 14)
• Program Memory Type: OTP
• Ram Size: 256 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 10x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 44-PLCC
• For Use With: DVA16XL441 - ADAPTER DEVICE ICE 44PLCC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: PIC16C774E/L

PIC16C77X
The RB3 pin is multiplexed with analog channel 9 and
the low voltage detect input (RB3/AN9/LVDIN)
FIGURE 3-7:
DS30275A-page 30
Data bus
WR TRIS
WR Port
To A/D converter and LVD reference input
RBPU
Note 1: I/O pins have diode protection to V
(2)
2: To enable weak pull-ups, set the appropriate TRIS bit(s)
and clear the RBPU bit (OPTION_REG<7>).
RD TRIS
Data Latch
TRIS Latch
D
D
CK
CK
BLOCK DIAGRAM OF
RB3/AN9/LVDIN PIN
RD Port
Q
Q
Q
Analog
input mode
or LVD input
mode
EN
D
DD
and V
TTL
Input
Buffer
RD Port
SS
Advance Information
.
V
P
DD
weak
pull-up
I/O
pin
(1)
Four of PORTB’s pins, RB7:RB4, have an interrupt on
change feature. Only pins configured as inputs can
cause this interrupt to occur (i.e. any RB7:RB4 pin con-
figured as an output is excluded from the interrupt on
change comparison). The input pins (of RB7:RB4) are
compared with the old value latched on the last read of
PORTB. The “mismatch” outputs of RB7:RB4 are
OR’ed together to generate the RB Port Change Inter-
rupt with flag bit RBIF (INTCON<0>).
This interrupt can wake the device from SLEEP. The
user, in the interrupt service routine, can clear the inter-
rupt in the following manner:
a)
b)
A mismatch condition will continue to set flag bit RBIF.
Reading PORTB will end the mismatch condition, and
allow flag bit RBIF to be cleared.
The interrupt on change feature is recommended for
wake-up on key depression operation and operations
where PORTB is only used for the interrupt on change
feature. Polling of PORTB is not recommended while
using the interrupt on change feature.
FIGURE 3-8:
Data bus
WR TRIS
WR Port
RBPU
Note 1: I/O pins have diode protection to V
RB7:RB6 in serial programming mode
Set RBIF
From other
RB7:RB4 pins
Any read or write of PORTB. This will end the
mismatch condition.
Clear flag bit RBIF.
2: To enable weak pull-ups, set the appropriate TRIS bit(s)
(2)
and clear the RBPU bit (OPTION_REG<7>).
RD TRIS
RD Port
Data Latch
TRIS Latch
BLOCK DIAGRAM OF
RB7:RB4 PINS
D
D
CK
CK
Q
Q
1999 Microchip Technology Inc.
Q
Q
Latch
DD
EN
EN
D
D
and V
TTL
Input
Buffer
SS
V
P
DD
.
weak
pull-up
RD Port
Buffer
I/O
pin
Q1
Q3
(1)
ST