CMX264D5 データシートの表示（PDF） - MX-COM Inc
部品番号
コンポーネント説明
メーカー
CMX264D5 Datasheet PDF : 22 Pages
| |||
Frequency Domain Split-Band Scrambler
9
CMX264 Advance Information
4.2.7 Rx Upperband Output Filter (RXUBOPF)
A lowpass filter whose function is to select the lower sideband output of the Rx upperband balanced
modulator. Its output is the upperband part of the descrambled signal which is summed with the output of the
lowerband Rx channel to form the complete descrambled signal.
4.2.8 Rx Summer
This sums the lowerband and upperband to form the complete descrambled audio signal.
4.2.9 Rx Channel De-Emphasis
A de-emphasis circuit at the output of the Rx descramble block. It has a slope of -6dB per octave between
280Hz and 3140Hz. It may be selected to de-emphasise the recovered (descrambled) audio signal. It may
be selected in conjunction with the pre-emphasis circuit at the input of the Tx scramble block.
4.3 Serial Interface
4.3.1 General Operation
The serial interface controls the internal states and modes of operation of the CMX264. Data is input to the
SDATA pin MSD (D10) first and is clocked into the device on the rising edge of SCLK. Only the last 11 bits of
data is loaded on the rising edge of CS . The bit functions are shown in Table 3. Also refer to the timing
diagram of Figure 10.
D10
Powersave
D9
Clear/Scramble
D8
MICO
Output
Control
D7
RECO
Output
Control
D6
EXTO
Output
Control
D5 D4 D3 D2
Pre/De-Emphasis
Select/Bypass
D1 D0
Split Point
Select
Table 3: General Operation
4.3.2 Powersave Mode (D10)
D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
1
X
X
X
X
X
X
X
X
X
X
Table 4: Powersave Mode
D10 = 1 powersaves the whole device, including the oscillator. All other bits become DON'T CARE when this
mode is selected.
On power up, the CMX264 automatically sets itself into the powersave state.
The host equipment should then select the operating mode via the serial interface at least 3ms after initial
power up. The delay is to allow the reset circuit to become dormant. This is the only occasion on which it
operates.
4.3.3 Clear/Scramble Modes (D9)
D10 D9 D8
D7
D6 D5 D4 D3 D2 D1 D0
0
1
MICO
RECO EXTO
X
X
X
X
X
X
Output Output Output
Control Control Control
Table 5: Clear Mode
D9 = 1 selects clear mode. The scramble, descramble, pre-emphasis and de-emphasis blocks in both Tx
and Rx channels are all bypassed. No signal processing or filtering is carried out.
All other bits become DON'T CARE except the output select bits (D8, D7, D6).
D10
0
D9
D8
D7
D6
D5 D4 D3 D2
0
MICO
RECO
EXTO
Output Control Output Control Output Control
Pre/De-Emphasis
Block Select
D1 D0
Split Point
Select
Table 6: Scramble Mode
2000 MX-COM, Inc.
www.mxcom.com tel: 800 638 5577 336 744 5050 fax: 336 744 5054
Doc. # 20480210.002
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA All Trademarks and service marks are held by their respective companies.
Share Link: 