AD1954 Analog Devices, AD1954 Datasheet - Page 27

• Manufacturer Part Number: AD1954
• Description: SigmaDSP Digital Audio Processor
• Manufacturer: Analog Devices

SPI READ/WRITE DATA FORMATS
The read/write formats of the SPI port are designed to be byte-
oriented. This allows for easy programming of common
microcontroller chips. To fit into a byte-oriented format, 0s are
appended to the data fields in order To extend the data word to
the next multiple of eight bits. For example, 22-bit words writ-
ten to the SPI parameter RAM are appended with two leading
zeroes to reach 24 bits (3 bytes), and 35-bit words written to
the program RAM are appended with five zeros to reach 40 bits
Byte 0
00000, Wb/R, adr[9:8]
Byte 0
00000,Wb/R, adr[9:8] adr[7:0]
Byte 0
00000, Wb/R, adr[9:8]
Byte 0
00000, Wb/R, adr[9:8]
Byte 0
00000, Wb/R, adr[9:8]
Byte 0
000000, adr[9:8]
Byte 0
00000, Wb/R, adr[9:8] adr[7:0] 00000, prog[34:32] prog[31:24] prog[23:16] prog[15:8] prog[7:0]
Byte 0
00000, Wb/R, adr[9:8]
Table IX. Parameter RAM Block READ/WRITE Format (Burst Mode)
Byte 1
Byte 1
Table XI. Program RAM Block READ/WRITE Format (Burst Mode)
Byte 1
adr[7:0]
Byte 1
adr[7:0]
Byte 1
adr[7:0]
Byte 1
adr[7:0]
PRELIMINARY TECHNICAL DATA
Table VIII. Parameter RAM READ/WRITE Format (Single Address)
Table X. Program RAM READ/WRITE Format (Single Address)
Byte 2
00000, prog[34:32]
Byte 2
Byte 1
adr[7:0] 00, param[21:16] param[15:8] param[7:0]
Table XIV. SPI Control Register 2 WRITE Format
Table XII. SPI Control Register 1 WRITE Format
Table XIII. SPI Control Register 1 READ Format
Table XV. SPI Volume Register WRITE Format
Byte 2
Byte 2
00, param[21:16]
Byte 2
00, volume[21:16]
Byte 1
adr[7:0]
Byte 3
Byte 3
prog[31:24]
Byte 2
00000, bit[10:8]
Byte 2
00000, bit[10:8]
Byte 3
(5 bytes). These zero-extended data fields are appended to a
2-byte field consisting of a read/write bit and a 10-bit address.
The SPI port knows how many data bytes to expect based on
the address that is received in the first two bytes.
The total number of bytes for a single-location SPI write command
can vary from four bytes (for a Control Register write), to seven
bytes (for a Program RAM write). Block writes may be used to
fill contiguous locations in Program RAM or Parameter RAM.
ADR
ADR
Byte 4
Byte 4
prog[23:16]
Byte 3
param[15:8]
Byte 3
volume[15:8]
Byte 4
Byte 5
Byte 5
prog[15:8]
Byte 6
Byte 5 Byte 8
Byte 6 Byte 9
Byte 7 Byte 10
ADR+1 ADR+2
Byte 2
000000, bit[1:0]
Byte 3
Byte 3
bit[7:0]
bit[7:0]
Byte 4
param[7:0]
Byte 7 Byte 12
Byte 8 Byte 13
Byte 9 Byte 14
Byte 10 Byte 15
Byte 11 Byte 16
ADR+1 ADR+2
Byte 4
volume[7:0]
AD1954
Byte 6
prog[7:0]