4 protocol and messages, 1 messages – Cirrus Logic CS1810xx User Manual
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©
Copyright 2005 Cirrus Logic, Inc.
DS651UM23
Version 2.3
CobraNet Hardware User’s Manual
Host Management Interface (HMI)
7.4
Protocol and Messages
The message conduit is used to issue commands to the CS1810xx/CS4961xx and
retrieve HMI status. The data conduit is used to transfer data dependent on the HMI state
as determined by commands issued by the host via the message conduit.
7.4.1 Messages
Messages are used to efficiently invoke action in the CS1810xx/CS4961xx. To send a
message, the host optionally writes to the A, B, and C registers. Writing to the D register
transmits the message to the CS1810xx/CS4961xx. A listing of all HMI messages is
shown in
. Refer also to
.
Table 4. HMI messages
Message
DRQ Handshake
Mode
A
B
C
D
Translate Address
n/c
Address (MS)
Address
Address (LS)
0xB3
Acknowledge Interrupt
n/c
n/c
n/c
n/c
0xB4
Identify
read
n/c
n/c
7
0xB5
Goto Packet Transmit
Buffer
write
n/c
n/c
6
0xB5
Goto Translation
write
n/c
n/c
5
0xB5
Acknowledge Packet
Receipt
n/c
n/c
n/c
4
0xB5
Transmit Packet
n/c
n/c
n/c
3
0xB5
Goto Counters
read
n/c
n/c
2
0xB5
Goto Packet Receive
Buffer
read
n/c
n/c
1
0xB5
Goto Translation
read
n/c
n/c
0
0xB5