Interrupt Service Routine (ISR) Flowcharts
13-112
Figure 13–34. Write Isochronous TX FIFO Data Flowchart
ISO TX handler
Read byte from
application’s TX
buffer.
Loop count = 0?
No
Write byte to TX
FIFO (via DATA
Increment TX byte
count, decrement
loop count.
Update application’s
TX buffer count.
Yes
End of TX ISO handler
STAT_FLG.
Miss_In
= 1 ?
Yes
No
Wish to resend
missed data?
Yes
Set
CTRL.Cir_EP to
clear the current
FIFO.
No
Set Loop_count to TX
ISO packet length
(max is endpoint size).
When a Missed_in occurs, missed
data are from TWO frames previous).
Application-
specific actions
to handle
missed in data
(Reload TX byte
count,...).
Must put missed transmit data
into foreground ISO TX FIFO.
Clear both foreground and
background TX FIFO.
register).