PIC16F74-E/PT Microchip Technology, PIC16F74-E/PT Datasheet - Page 482

• Manufacturer Part Number: PIC16F74-E/PT
• Description: IC MCU FLASH 4KX14 A/D 44TQFP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F74-E/PT

• 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: FLASH
• Ram Size: 192 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x8b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Other names: PIC16F74E/PT

PICmicro MID-RANGE MCU FAMILY
25.15
DS31025A-page 25-24
Design Tips
Question 1:
Answer 1:
Ensure that you have the control bits in the LCDSE properly configured, since these bits override
the TRIS bits.
Question 2:
Answer 2:
Your frame frequency may be too low. The frame frequency can be changed in the LCDPS
register.
Question 3:
Answer 3:
This may be due to misadjusted LCD voltage, some possibilities include:
1.
2.
If you are using the R-ladder, try different values of R, vary the R-ladder potentiometer.
The VLCDADJ pin should be connected to ground.
If you are using the charge pump, adjust the resistance value on the VLCDADJ pin.
I’m trying to use some of the LCD pins as inputs.
My LCD panel is flickering.
The LCD segments are not very visible.
1997 Microchip Technology Inc.