Altera DisplayPort MegaCore Function - Manual (Page 142)

For transaction replies:
1. Issue a transaction request.
2. Wait for
MSG_READY
to be 1. Implement a timeout.
3. Read the transaction reply’s total length from
LENGTH
.
4. Read the transaction reply's command from the
DPTX_AUX_COMMAND
register. This transaction clears
MSG_READY
and
LENGTH
.
5. Read the transaction reply's data payload from registers
DPTX_AUX_BYTE0
to
DPTX_AUX_BYTE15
(read
LENGTH
- 1 bytes).
Address: 0×0100
Direction: RW
Reset: 0×00000000
Table 9-39: DPTX_AUX_CONTROL Bits
Bit Bit Name Function
31 MSG_READY 0 = Waiting for a reply
1 = A reply has been completely received
30 READY_TO_TX 0 = Busy sending a request or waiting for a reply
1 = Ready to send a request
29:5 Unused
4:0 LENGTH For the next transaction request, total length of message to
be transmitted (3 – 20), for the last received transaction
reply, total length of message received (1 – 17).
DPTX_AUX_CMD
Address: 0×0101
Direction: RW
Reset: 0×00000000
Table 9-40: DPTX_AUX_CMD Bits
Bit Bit Name Function
31:8 Unused
7:0 COMMAND AUX transaction command for the next request or
received in the most recent reply (refer to the Display‐
Port specification for details). Reading of this register
clears
MSG_READY
and
LENGTH
in
DPTX_AUX_CONTROL
register.
UG-01131
2015.05.04
DPTX_AUX_CMD 9-21
DisplayPort Source Register Map and DPCD Locations Altera Corporation
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