© 2000 Ubicom, Inc. All rights reserved. - 23 - www.ubicom.com SX IrDA Virtual Peripheral Implementation AN16 5.0 Serial Port / Debug The demonstration PCB includes a RS232 serial port for
debug  and  external  communication.  The  UART-Virtual
Peripheral    supports    full    duplex    communication    at
115200bps (1 start bit, no parity, 1 stop bit) with no hand-
shaking  (RTS/CTS  hand-shaking  is  supported  by  the
hardware but has not been implemented in software).
A data byte can be transmitted using the following code: mov UartTxData, w setb UartTxStart The register and bit are both global (no bank instruction
needed). Debug data is the same as UartTxData and DebugSend  is  the  same  as  UartTxStart.  When  the data  byte  has  been  sent  the  global  UartTxEmpty  flag
will be set.
If the UART is idle then the transmission will start at the
next timer interrupt (108 cycles @ 50MHz), otherwise it
will  start  once  the  current  byte  is  finished.  There  is  no
additional buffering and so a second byte cannot be sent
until the first byte has started transmission (indicated by UartTxStart being cleared). When a data byte is received the global  UartRxAvail
flag will be set. The received data byte is in the UartRx- Data register in the IsrBank (not global). 5. 1 DEBUG MACROS Table 5-1 shows three debug macros for showing debug
data. The first parameter is a constant and must be 1 for the
macro to take affect. Debug Information The  debug  control  registers  in  ‘PROJECT.SRC’  can  be
changed to show more debug information. Table 5-1.    Debug Macros Name Description Example Affects Words Cycles Debug Output the value in w debug 1 none 2 2 Debugl Output a literal value debugl l, ‘!’ w 3 3 Debugf Output the given register debugf 1, reg w, z 3 3