AD1821 Analog Devices, AD1821 Datasheet - Page 27

• Manufacturer Part Number: AD1821
• Manufacturer: Analog Devices

[Base+9]
CEN
CIO
CST
CC/L
CFMT [1:0]
[Base+10]
[Base+11]
[Base+12]
Joystick Data (RO)
[Base+13]
JMSK [3:0]
JSEL [1:0]
Note: Sampling must be started manually if JWRP is set before any sampling cycles are run. To start sampling after setting the JWRP
bit, write to the joystick port [Base+14].
REV. 0
JWRP
JRDY
JRDY
Reserved
Joystick RAW DATA
Joystick Control
(RW)
(RW)
(RW)
(RO)
Capture Configuration
(RW) Capture Enable. This bit enables or disables data capture.
(RW) Capture Programmed I/O. This bit determines whether the capture data is transferred via DMA or PIO.
(RW) Capture Stereo/Mono Select. This bit selects stereo or mono formatting for the input audio data streams.
(RW) Capture Companded/Linear Select. This bit selects between a linear digital representation of the audio sig-
(RW) Capture Format. Use these bits to select the format for capture data according to the following Table VI and
Reserved
7
7
7
7
7
RES
0
1
0
1
In stereo, the Codec alternates samples between channels to provide left and right channel input. For mono,
the Codec captures samples on the left channel.
0
1
nal or a nonlinear, companded format for all output data. The type of linear PCM or the type of companded
format is defined by CFMT [1:0].
0
1
Figure 15.
Joystick Data. Joystick Data (identical to 0x201): Writes to this register are ignored.
Joystick Axis Mask. JRDY bit calculated based on axes selected by JMSK only.
Joystick Select. Selects one of four joystick axis register sets according to the following table:
Joystick Wrapmode. Continuous Joystick sampling mode—sampling automatically restarted every ~16 ms.
Joystick Ready. Sampling complete, joystick data ready for reading.
JWRP
6
6
6
6
6
Linear PCM
Disable
Enable
DMA
PIO
Mono
Stereo
Companded
00
01
10
11
CFMT [1:0]
5
5
5
5
5
JSEL [1:0]
Joystick Data [7:0]
Read AX (16 Bits) from [Base+14] & [Base+15]
Read AY (16 Bits) from [Base+14] & [Base+15]
Read BX (16 Bits) from [Base+14] & [Base+15]
Read BY (16 Bits) from [Base+14] & [Base+15]
RESERVED
RESERVED
4
4
4
4
4
xxx1
xx1x
x1xx
1xxx
CC/L
3
3
3
3
3
–27–
Enable AX
Enable AY
Enable BX
Enable BY
CST
2
2
2
2
2
JMSK [3:0]
CIO
1
1
1
1
1
CEN
0
0
0
0
0
RESET = [0xXX]
RESET = [0xXX]
RESET = [0xF0]
RESET = [0x00]
RESET = 0xF0
AD1821