Motorola MPC533 Reference Manual page 679

Transmit Queue Enabled
1
QTSZ=1111 (16 Data Frames)
QTPNT
0000
SCTQ[0]
SCTQ[7]
0111
SCTQ[8]
1000
SCTQ[15]
1111
QBHE Interrupt Received
3
(Wrap Occurred)
QTSZ=1000 (9 Data Frames)
QTPNT
0000
SCTQ[0]
SCTQ[7]
0111
SCTQ[8]
1000
SCTQ[15]
1111
Load QPEND with QTSZ
Clear QTWE
Reset QTPNT
Write SCTQ[8]
Clear QBHE
Figure 15-37. Queue Transmit Example for 25 Data Frames
MOTOROLA
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
2
QTHE Interrupt Received
QTSZ=1111 (16 Data Frames)
QPEND QTPNT
1111 0000
0111
1000
0111 1000
0000 1111
QTHE Interrupt Received
4
QTSZ=1000 (9 Data Frames)
QPEND QTPNT
0000
1000
0111
0001
1000
0000
1001
1111
Chapter 15. Queued Serial Multi-Channel Module
QPEND
1111
SCTQ[0]
SCTQ[7]
1000
SCTQ[8]
0111
SCTQ[15]
0000
Write QTSZ = 8 (16 + 9 = 25)
Write SCTQ [0:7] for 8 More Data Frames
Set QTWE
Clear QTHE
QPEND
1000
SCTQ[0]
SCTQ[7]
0001
SCTQ[8]
0000
1111
SCTQ[15]
SCI Queue Operation
Data to be Transferred
Available Register Space
15-73