PC87108AVJE NSC [National Semiconductor], PC87108AVJE Datasheet - Page 40

• Manufacturer Part Number: PC87108AVJE
• Description: Advanced UART and Infrared Controller
• Manufacturer: NSC [National Semiconductor]

www.national.com
3.0 Architectural Description
3.8.3 RCCFG – CEIR Configuration Register
This register controls the basic operation of the CEIR mode.
After reset, all bits are set to 0.
B1–0 RC__MMD [1–0] – Transmitter Modulation Mode.
B2 TXHSC – Transmitter Subcarrier Frequency Select.
B3 Reserved.
B4 RCDM__DS – Receiver Demodulation Disable.
B5 RXHSC – Receiver Subcarrier Frequency Select.
B6 T__0V – Receiver Sampling Mode.
B7 R__LEN – Run-Length Control.
Reset State
Determines how infrared pulses are generated from the transmitted bit string.
00
01
10
11
Selects the frequency range for the modulation subcarrier.
0
1
Write 0.
When this bit is 1, the internal demodulator is disabled. The internal demodulator, when enabled, performs subcarrier fre-
quency checking and envelope generation.
It must be disabled when demodulation is done externally, or when oversampling mode is used to determine the subcarrier
frequency.
Selects the frequency range for the receiver demodulator.
0
1
0
1
When set to 1, run-length encoding/decoding is enabled.
The format of a run-length code is YXXXXXXX, where:
Y - Bit value
XXXXXXX — Number of bits minus 1.
Function
Bits
30–56.9 kHz
400–480 kHz
30–56.9 kHz
400–480 kHz
Programmed-T-period sampling.
Oversampling Mode.
Reserved.
Result is indeterminate.
C__PLS Modulation Mode.
Pulses are generated continuously for the entire
logic 0 bit time.
8__PLS Modulation Mode.
8 pulses are generated each time one or more
logic 0 bits are transmitted following a logic 1 bit.
6__PLS Modulation Mode.
6 pulses are generated each time one or more
logic 0 bits are transmitted following a logic 1 bit.
Encoding
(Selects 1 to 128 bits).
110
111
R__LEN
B7
0
T__OV
B6
0
Low Frequency, TXHSC = 0
FIGURE 30. CEIR Configuration Register
(Consumer-IR only)
RXHSC
B5
Reserved
Reserved
(Continued)
0
RCDM__DS
40
B4
0
res
B3
0
High Frequency, TXHSC = 1
(Consumer-IR or Sharp-IR)
TXHSC
B2
0
Reserved
Reserved
RC__MMD1
B1
0
RC__MMD0
B0
0