Rainbow Electronics AT86RF231 - Manual (Page 64)

64
8111A–AVR–05/08
AT86RF231
7.2.4 TX_ARET_ON - Transmit with Automatic Retry and CSMA-CA Retry
Figure 7-12. Flow Diagram of TX_ARET
TRX_STATE = TX_ARET_ON
csma_rctr = 0
TRX_STATE = TX_ARET_ON
N
Y
Failure
Success
N
Y
frame_rctr = 0
Transmit Frame
frame_rctr = frame_rctr + 1
Y
N
N
Y
TRAC_STATUS =
NO_ACK
TRAC_STATUS =
SUCCESS
TRAC_STATUS =
CHANNEL_ACCESS_FAILURE
Issue IRQ_3 (TRX_END) interrupt
CCA
Result
ACK requested
ACK valid
TRAC_STATUS =
SUCCESS_DATA_PENDING
Y
N
Receive ACK
until timeout
Y
N
TRX_STATE = BUSY_TX_ARET
TRAC_STATUS = INVALID
MAX_CSMA_RETRIES
<7
Y
N
csma_rctr >
MAX_CSMA_RETRIES
Y
Note 1: If MAX_CSMA_RETRIES = 7 no retry is
performed (see Note 1)
Random Back-Off
csma_rctr = csma_rctr + 1
CCA
Start TX
frame_rctr >
MAX_FRAME_RETRIES Data Pending
N