MSK Modem
20
MX809
7.1.4 Timing
C-BUS Timing
Min.
2.0
Typ.
Max.
Units
t
t
t
t
t
t
Chip Select Low to First Serial Clock Rising Edge
Last Serial Clock Rising Edge to Chip Select High
Chip Select High to Reply Data High -Z
Chip Select High time between transactions
Inter-Byte Time
ꢃs
ꢃs
CSE
CHS
HIZ
4.0
2.0
2.0
4.0
2.0
ꢃs
ꢃs
ꢃs
CSOFF
NXT
CK
Serial Clock Period
Table 12: Timing Information
Notes:
1. Depending on the command, 1 or 2 bytes of Command Data is transmitted to the peripheral MSB (bit 7)
first, LSB (bit 0) last. Reply Data is read from the peripheral MXB (bit 7) first, LSB (bit 0) last.
2. Data is clocked into and out of the peripheral on the rising Serial Clock edge.
3. Loaded commands are acted upon at the end of each command.
4. To allow for differing microcontroller serial interface formats, C-BUS compatible ICs are able to work with
either polarity Serial Clock pulses.
tCSOFF
CHIP SELECT
tCSE
tCSH
tNXT
tNXT
SERIAL CLOCK
tCK
COMMAND DATA
7
6
6
5
4
3
2
1
1
0
7
6
5
4
3
2
1
0
7
6
6
5
4
3
2
1
1
0
MSB
LSB
MSB
LSB
MSB
LSB
FIRST DATA BYTE
LAST DATA BYTE
ADDRESS/COMMAND
BYTE
ä
ä
tHIZ
REPLY DATA
7
5
4
3
2
0
7
5
4
3
2
0
MSB
LSB
MSB
LSB
FIRST REPLY DATA BYTE
LAST REPLY DATA BYTE
Logic level is not important
Figure 11: C-BUS Timing Information
ꢀ1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
Doc. # 20480036.004
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
All trademarks and service marks are held by their respective companies.
CMLMICRO [ CML MICROCIRCUITS ]
