4 operating system (os) firmware module – Cirrus Logic AN333 User Manual
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AN333
4 Operating System (OS) Firmware Module
4 Operating System (OS) Firmware Module
Figure 4-1. Unsolicited Read Command and Data Words
describes the API used to control the OS firmware module. Indices of the Firmware Module can differ in
properties that are important to the system firmware programmer.
Variables marked by a ‘†’ can be modified after kick-starting the application. However, variables not marked by a ‘†’ must
be configured by the system host controller before the kick-start message is sent to begin decoding. For these indices,
changes after kick-starting the application do not have the desired effect and can potentially cause the application to
become unstable.
All indices are reinitialized to the default values after downloading the overlay and soft-resetting the overlay.
Index = 0xHHHH, data value = 0xhhhhhhhh
Write = 0x8100HHHH 0xhhhhhhhh
Read Request = 0x81C0HHHH
Read Response = 0x01C0HHHH 0xhhhhhhhh
Unsolicited Read Command Word:
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
OPCODE[31:16]
INDEX[15:0]
Unsolicited Read Data Word:
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
DATA WORD[31:0]