Timing Information
Timing Diagrams
Figure 9 shows the timing parameters for two-way communication between the µController and the FX805 on the “C-BUS.”
Figure 10 shows, in detail, the timing relationships for “C-BUS” information transfer.
t CSOFF
CHIP SELECT
t CSE
t NXT
t NXT
t CK
t CSH
SERIAL CLOCK
COMMAND DATA
7
6
5
4
3
2
1
0
7
6
6
5
4
3
2
1
1
0
7
7
6
6
5
4
3
2
1
1
0
0
MSB
LSB
ADDRESS/COMMAND
BYTE
FIRST DATA BYTE
LAST DATA BYTE
REPLY DATA
t HIZ
7
5
4
3
2
0
5
4
3
2
MSB
LSB
FIRST REPLY DATA BYTE
LAST REPLY DATA BYTE
Logic level is not important
Fig.9 “C-BUS” Timing Information
NOT TO SCALE
Parameter
Min.
Typ.
Max.
Unit
tCSE
tCSH
tCSOFF
tNXT
tCK
2.0
4.0
2.0
4.0
2.0
500
500
250
0
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
–
µs
µs
µs
µs
µs
ns
ns
ns
ns
ns
ns
µs
tCH
tCL
tCDS
tCDH
tRDS
tRDH
tHIZ
250
50.0
–
–
–
2.0
Notes
(1) Command Data is transmitted to the peripheral MSB (bit 7) first, LSB (bit 0) last.
Reply Data is read from the FX805 MSB (bit 7) first, LSB (bit 0) last.
(2) Data is clocked into the FX805 and into the µController on the rising Serial Clock edge.
(3) Loaded data instructions are acted upon at the end of each individual, loaded byte.
(4) To allow for differing µController serial interface formats, the FX805 will work with either polarity Serial
Clock pulses.
tCK
tCL
70% V
DD
SERIAL CLOCK
(from µC)
30% V
DD
tCH
tCDH
tCDS
COMMAND DATA
(from C)
µ
tRDH
tRDS
REPLY DATA
(to C)
µ
Fig.10 “C-BUS” Timing Relationships
NOT TO SCALE
13
CMLMICRO [ CML MICROCIRCUITS ]
