© 2001 Ubicom, Inc. All rights reserved. - 3 - www.ubicom.com Asynchronous Transmitter & Receiver (UART) Virtual Peripheral Implementation AN38 3.2           Bank Section
This section describes the use of the register banks in the UART Virtual Peripheral.
Inside this bank we have different banks for RS232TX, RS232RX, and Multiplex for clarity. Although there are three
banks, because all three are declared within bank 1, bank 1 becomes the current bank whenever any of these three
banks are accessed. Using different defines for each module allows the RAM definitions to be moved around in the
future to make space for other Virtual Peripherals in the same application. Org                             bank1_org
; VP: VP Begin          RS232 Transmit rs232TxBank = $ ;UART    bank rs232TxHigh ds 1 ;hi byte to transmit rs232TxLow ds 1 ;low byte to transmit rs232TxCount ds 1 ;number of bits sent rs232TxDivide ds 1 ;x’mit timing (/16) counter Rs232TxFlag ds 1 ;VP: END ;VP : VP Begin          RS232 Receive rs232RxBank = $ rs232RxCount ds 1 ;number of bits received rs232RxDivide ds 1 ;receive timing counter rs232RxByte ds 1 ;buffer for incoming byte rs232Byte ds 1 ;used by serial routines hex ds 1 ;VP: END
;VP : VP Begin          Multiplexer MultiplexBank = $ isrMultiplex    ds         1   ;VP: END