Cypress AN2034 - Manuals

AN2034 January 16, 2009 Document No. 001-40409 Rev. *A 2 PSOC General Purpose IO To detect single-switch closures, use the following algorithm: ƒ Drive all rows simultaneously and read the columns. ƒ Drive all columns simultaneously and read the rows. ƒ Condense this data to determine switch-closure...

AN2034 January 16, 2009 Document No. 001-40409 Rev. *A 3 Code 1: Subroutine for Reading Keypad ;----------------------------------------- ; Keypad.asm ; ; This routine reads a 4 column by 4 row ; keypad on port1. The status of key ; closures is returned in A. ; ; P1.4 P1.5 P1.6 P1.7 ; C0 C1 C2 C3 ; ...

AN2034 January 16, 2009 Document No. 001-40409 Rev. *A 4 Example Code 3 is the main function that implements the design in Figure 5 on page 3. Code 3. Keypad Project Implemented ;----------------------------------------- ; This program reads the keypad ; at port 1 and control the LEDs ; on port0. ; ...