AN2262 Motorola / Freescale Semiconductor, AN2262 Datasheet - Page 25

• Manufacturer Part Number: AN2262
• Description: Wireless HC08 Modem
• Manufacturer: Motorola / Freescale Semiconductor

MOTOROLA
NOTES:
During transmit initialization the flags are set as follows:
If RFTimerTxd_Int flag is not cleared during this interrupt service, this routine is immediately called again. This is NOT a
bug, it’s intended to simplify the routine implementation.
‘preamble’ flag is set, ‘header’ flag is set, ‘tail’ flag is cleared, txBits is zeroed
RETURNS NEXT BYTE
TO SEND — FEEDS
(ZERO IF NO DATA
TxChar AND TxBits
RF_TxChar_Int()
ANY SPECIAL
RF TX FLAG
SET ‘TAIL’ FLAG
TO SEND)
TxBits
RETURN
= 0
NO
= 0
CLEAR RFTIMERTXD_INT FLAG
Figure 15. Main Transmit Interrupt Service Routine Flowchart
PREPARE EDGE/LEVEL REGS’
(NO DATA TO SEND)
WITH NEXT BIT VALUE
DECREMENT TXBITS
YES
> 0
TXBITS
RETURN
RETURN
> 0
> 0
SHIFT-IN TRANSMIT CHAR
Wireless HC08 Modem
RFTIMERTXD_INT
RETURN
TXBITS
CLEAR RFTIMERTXD_INT FLAG
TXFINISH() CLEANUP
= 0
‘PREAMBLE’ FLAG
‘HEADER’ FLAG
‘TAIL’ FLAG
RETURN
NO
NO
NO
YES
YES
YES
CLEAR ‘PREAMBLE’ FLAG
FEED TxChar AND TxBits
CLEAR ‘HEADER’ FLAG
FEED TxChar AND TxBits
PREAMBLE VALUES
CLEAR ‘TAIL’ FLAG
WITH CORRECT
HEADER VALUES
WITH CORRECT
RETURN
RETURN
RETURN
AN2262/D
Software
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