Cs4205 – Cirrus Logic CS4205 User Manual
Page 21
CS4205
DS489PP4
21
4.1.3
Command Data Port (Slot 2)
WD[15:0]
Write Data. The WD[15:0] bits contain the 16-bit value to be written to the register. If an ac-
cess is a read, this slot is ignored.
NOTE:
For any write to an AC ’97 register, the write is defined to be an ‘atomic’ access. This means
that when the Slot 1 Valid bit in output Slot 0 is ‘set’, the Slot 2 Valid bit in output Slot 0 should
always be ‘set’ during the same audio frame. No write access may be split across 2 frames.
4.1.4
PCM Playback Data (Slots 3-11)
PD[19:0]
Playback Data. The PD[19:0] bits contain the 20-bit PCM (2’s complement) playback data for
the left and right DACs, serial data ports, and/or the S/PDIF transmitter. Table 14 on page 43
lists a cross reference for each function and its respective slot. The mapping of a given slot
to the DAC, serial data port, or S/PDIF transmitter is determined by the state of the ID[1:0]
bits in the Extended Audio ID Register (Index 28h) and by the SM[1:0] and AMAP bits in the
AC Mode Control Register (Index 5Eh).
4.1.5
GPIO Pin Control (Slot12)
GPIO[4:0]
GPIO Pin Control. The GPIO[4:0] bits control the CS4205 GPIO pins configured as outputs.
Write accesses using GPIO pin control bits configured as outputs will be reflected on the
GPIO pin output on the next AC-link frame. Write accesses using GPIO pin control bits con-
figured as inputs will have no effect and are ignored. If the GPOC bit in the Misc. Crystal Con-
trol Register (Index 60h) is ‘set’, the bits in output Slot 12 are ignored and GPIO pins
configured as outputs are controlled through the GPIO Pin Status Register (Index 54h).
Bit 19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
WD15 WD14 WD13 WD12 WD11 WD10 WD9 WD8 WD7 WD6 WD5 WD4 WD3 WD2 WD1 WD0
Reserved
Bit 19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
PD19 PD18 PD17 PD16 PD15 PD14 PD13 PD12 PD11 PD10 PD9 PD8 PD7 PD6 PD5 PD4 PD3 PD2 PD1 PD0
Bit 19 18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Not Implemented
GPIO4 GPIO3 GPIO2 GPIO1 GPIO0
Reserved