User manual

...the world's most energy friendly microcontrollers
2012-04-24 - Giant Gecko Family - d0053_Rev0.96 278
www.energymicro.com
Figure 15.17. Normal Isochronous OUT/IN Transactions in Slave Mode
HostApplication DeviceAHB USB
O
U
T
D
A
T
A
0
M
P S
1
MPS
1
MPS
write_tx_fifo
(ch_1)
init_reg(ch_1)
set_ch_en
(ch_2)
init_reg(ch_2)
write_tx_fifo
(ch_1)
ch_2
ch_1
I
N
O
U
T
D
A
T
A
0
M
P S
1
5
D
A
T
A
0
I
N
1
MPS
read_rx_sts
read_rx_fifo
read_rx_sts
1
2
3
4
6
2
3
6
7
8
9
init_reg(ch_1)
set_ch_en
(ch_2)
init_reg(ch_2)
write_tx_fifo
(ch_1)
init_reg(ch_1)
1
MPS
D
A
T
A
0
5
4
ch_2
ch_1
Even
frame
Odd
frame
XFERCOMPL interrupt
XFERCOMPL interrupt
XFERCOMPL interrupt
RXFLVL int errupt
RXFLVL int errupt
Periodic Re quest s
Queue
Asum e that this queue
can hold 4 entries.
Interrupt Service Routine for Isochronous OUT Transactions in Slave Mode
Isochronous OUT
Unmask (FRMOVRUN/XFERCOMPL)
if (XFERCOMPL)
{
De-allocate Channel
}
else if (FRMOVRUN)
{
Unmask CHHLTD
Disable Channel
}
else if (CHHLTD)
{
Mask CHHLTD
De-allocate Channel
}