Microchip Technology MCP3421EV 数据表
© 2009 Microchip Technology Inc.
DS22003E-page 21
MCP3421
FIGURE 5-4:
Timing Diagram For Reading From The MCP3421 With 12-Bit to 16-Bit Modes.
1
1
0
1
A2
A1
A0
ACK
by
M
C
P
3421
St
a
rt
B
it
b
y
Maste
r
2nd Byt
e
U
p
per Dat
a
B
y
te
AC
K
b
y
Mast
er
AC
K by
Maste
r
D
15
D
14
D
13
D
12
D
11
D
10
D
9
D
8
D
7
D
6
D
5
D
4
D
3
D
2
D
1
D
0
C
1
C
0
S
1
S
0
G
1
G
0
1st
B
y
te
MCP342
1 A
ddre
s
s
Byte
3rd
B
y
te
Lower
Dat
a
B
y
te
4t
h Byt
e
C
o
nf
igura
tio
n Byte
(O
pt
ional
)
C
1
C
0
S
1
S
0
G
1
G
0
NAK
b
y
Maste
r
S
top Bi
t by
Master
(O
pti
onal)
Nth Repe
ate
d
Byte
:
Co
nfi
gura
tio
n B
y
te
Note:
– MCP3
421
de
vice code is
1101
.
– Se
e
for
det
a
ils in Addr
ess
Byte.
– S
top bi
t or NAK
b
it
can
b
e
issued an
y
time duri
ng readi
ng.
– In 14
- bit mo
de: D15 an
d
D
14 are repe
ated MSB an
d ca
n be ign
o
red
.
– In 12
- bit mo
de: D15 - D12 are repe
ated MSB an
d can be ign
o
red
.
– Configu
ration byte repe
at
s as lon
g
a
s
clo
ck
is provi
ded af
ter
the
4
th byte.
9
1
99
1
9
1
9
1
SCL
SDA
9
1
RD
Y
O
/C
R/W
RDY
O
/C
T
o
cont
inue
: ACK by Maste
r
T
o
en
d: NAK by Maste
r