PIC16F1937-I/P Microchip Technology, PIC16F1937-I/P Datasheet - Page 20

• Manufacturer Part Number: PIC16F1937-I/P
• Description: IC PIC MCU FLASH 512KX14 40-PDIP
• Manufacturer: Microchip Technology
• Series: PIC® XLP™ 16Fr

Specifications of PIC16F1937-I/P

• Program Memory Type: FLASH
• Program Memory Size: 14KB (8K x 14)
• Package / Case: 40-DIP (0.600", 15.24mm)
• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 32MHz
• Connectivity: I²C, LIN, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 36
• Eeprom Size: 256 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 14x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Processor Series: PIC16F
• Core: PIC
• Data Bus Width: 8 bit
• Data Ram Size: 512 B
• Interface Type: EUSART/MI2C/SPI
• Maximum Clock Frequency: 32 MHz
• Number Of Programmable I/os: 36
• Number Of Timers: 5
• Maximum Operating Temperature: + 85 C
• Mounting Style: Through Hole
• 3rd Party Development Tools: 52715-96, 52716-328, 52717-734
• Development Tools By Supplier: PG164130, DV164035, DV244005, DV164005
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 14-ch x 10-bit
• A/d Bit Size: 10 bit
• A/d Channels Available: 14
• Height: 4.95 mm
• Length: 53.21 mm
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 1.8 V
• Width: 14.73 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

APPENDIX C:
;
; Purpose of routine is to evaluate
;
;
; X1 =
;
;
; Such as A+B = 2^n
;
; Simplified this formula will then become
;
;
; X1 =
;
;
; Where:
;
; X0 - is previous lowpassed filter value
; Y
; A,B are weight factors, if A is large relative to B
; then more emphasis is placed on the average ( filtered ) value.
; If B is large then the latest sample are given more weight.
; ~A is A's bitwise complement
;
;
; X0,X1,Y are 24 bit variables
; A+B = 2^8 = 256 for this routine
;
; By Tony Kübek 2000-05-23, based on routine 'twist.asm' by
; Scott Dattalo ( BTW Thanks for sharing :-) )
;
; ****************************************************************
;
; NewSample = Y ( 4 byte ram, 3 byte data )
; OldFilter = X0 ( 4 byte ram, 3 byte data )
; NewFilter = X1 ( 4 byte ram, 3 byte data )
; FilterWeight = A ( 1 byte ram, how much weight that is placed on old filtered value )
;
; * variables not really needed but used in example *
; FilterCounter = 1 byte, counter to increase step response.
; UpdateCounter = 1 byte, how many samples between 'global' updates
; AD_NewValue = 3 byte ram, last 24 bit reading from AD/or similar ( copied
; to NewSample, in case AD_NewValue should be used for other purposes )
; AD_DataVal = 3 byte ram, filtered value updated after UpdateCounter samples
; _AD_DataReady = 1 bit, set when AD_DataVal is updated
;
DS41375A-page 20
************************* TWIST24 ******************************
X1 - is new recursive lowpassed filter value
A*X0 + B*Y
A*X0 + ~A*Y + Y
- is new value
2^n
---------
A + B
---------------
24-BIT 256 STEP IIR FILTER (ORIGINAL CODE)
© 2009 Microchip Technology Inc.