CMX138 CML Microcircuits, CMX138 Datasheet - Page 70

• Manufacturer Part Number: CMX138
• Description: Audio Scrambler and Sub-Audio Signalling Processor
• Manufacturer: CML Microcircuits

Audio Scrambler and Sub-Audio Signalling Processor
11.2 C-BUS Timing
t
t
t
t
t
t
t
t
t
t
t
t
t
Notes:
These timings are for the latest version of C-BUS and allow faster transfers than the original C-BUS
timing specification. The CMX138 can be used in conjunction with devices that comply with the slower
timings, subject to system throughput constraints.
© 2008 CML Microsystems Plc
C-BUS Timing
CSE
CSH
LOZ
HIZ
CSOFF
NXT
CK
CH
CL
CDS
CDH
RDS
RDH
1. Depending on the command, 1 or 2 bytes of COMMAND DATA are transmitted to the
2. Data is clocked into the peripheral on the rising SERIAL_CLOCK edge.
3. Commands are acted upon at the end of each command (rising edge of CSN).
4. To allow for differing µC serial interface formats C-BUS compatible ICs are able to work
5. Maximum 30pF load on IRQN pin and each C-BUS interface line.
CSN Enable to SClk high time
Last SClk high to CSN high time
SClk low to ReplyData Output Enable
Time
CSN high to ReplyData high impedance
CSN high time between transactions
Inter-byte time
SClk cycle time
SClk high time
SClk low time
Command Data setup time
Command Data hold time
Reply Data setup time
Reply Data hold time
peripheral MSB (Bit 7) first, LSB (Bit 0) last. REPLY DATA is read from the peripheral MSB
(Bit 7) first, LSB (Bit 0) last.
with SERIAL_CLOCK pulses starting and ending at either polarity.
Figure 18 C-BUS Timing
Page 70
Notes
Min.
100
100
200
200
100
100
0.0
1.0
75
25
50
–
0
Typ.
–
–
–
–
–
–
–
–
–
–
–
–
–
Max.
1.0
–
–
–
–
–
–
–
–
–
–
–
–
D/138_FI1.0/5
Unit
ns
ns
ns
µs
µs
ns
ns
ns
ns
ns
ns
ns
ns
CMX138