cx25840 Conexant Systems, Inc., cx25840 Datasheet - Page 101

• Manufacturer Part Number: cx25840
• Description: Video Decoder And Broadcast Audio
• Manufacturer: Conexant Systems, Inc.

CX25840/1/2/3 Data Sheet
Figure 3-28. Input Signals Connection and Routing to Pins
Figure 3-29. Reading the Value of Pin 22 (FIELD/PRGM1) on Register 0x126 (GPI0)
102284B
8/3/05
Pin #
23
22
21
18
10
8
9
7
4
44
39
46
DVALID/PRGM0
FIELD/PRGM1
HRESET/PRGM2
VRESET/HCTL/PRGM3
IRQ_N/PRGM4
IR_TX/PRGM6
IR_RX/PRGM5
GPIO[0]PRGM8
GPIO[1]PRGM9
SA_SDIN
SA_SDOUT
PLL_CLK_PRGM7
Name
Pins
Register
Enable
114
114
115
115
114
114
114
114
114
115
115
116
Any of the pins shown in
For example, if you want to read the value of pin 22 (FIELD/PRGM1) on register
0x126 (GPI0), enable the pin by setting bit 7 of register 0x114, then program the input
mux to value 0001 of register 0x124, bits 3:0 (normally defaults to GPIO[0]. The
value of pin 22 (FIELD/PRGM1) can now be read. See
Bit
6
7
0
1
3
5
4
0
1
4
7
2
Enable bit 7 of register 114.
Program bits 3:0 of register 124 (GPI0_IN_SEL) to 0001.
Input Mux Select Value
FIELD/PRGM1
Pin 22
Binary
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
Bit
0
1
2
3
4
5
6
7
8
9
A
B
Conexant
Figure 3-28
Input Mux: Registers Monitoring Any Pin
Name
GPI0_IN_SEL
GPI1_IN_SEL
GPI2_IN_SEL
GPI3_IN_SEL
Register 126, Bit 7
can be routed to any four registers.
Register
0x124
0x124
0x125
0x125
GPI0
Bits Default (0000)
3:0
7:4
3:0
7:4
GPIO [0]
GPIO [1]
IR_RX/PRGM5
PLL_CLK/PRGRM7
Figure
Detailed Functional Description
3-29.
Inputs
GPI0
GPI1
GPI2
GPI3
Register 126
102284_061
Bit Location
102284_057
7
6
5
4
3-75