2003 Microchip Technology Inc.
DS39582B-page 103
PIC16F87XA
FIGURE 9-22:
I
2
C MASTER MODE WAVEFORM (RECEPTION, 7-BIT ADDRESS)
P
9
8
7
6
5
D0
D1
D2
D3
D4
D5
D6
D7
S
A7
A6
A5
A4
A3
A2
A1
SDA
SCL
12
3
4
5
6
7
8
9
12
3
4
5
67
8
9
12
3
4
Bu
s
m
a
s
te
r
te
rm
inat
es
tr
ans
fer
ACK
Re
ce
ivin
g
Da
ta
fr
o
m
Sla
v
e
Re
c
e
ivin
g
Da
ta
fr
o
m
Sla
v
e
D0
D1
D2
D3
D4
D5
D6
D7
ACK
R/W
=
1
T
ransm
it A
d
d
re
ss to
S
lave
SSPI
F
BF
AC
K
is no
t sen
t
W
rit
e
t
o
SS
PCO
N
2
<
0
>
(
SEN =
1
),
W
ri
te to S
S
P
B
U
F occu
rs here
,
ACK
f
ro
m
Sla
v
e
Master
c
o
nfi
gure
d
as a re
cei
v
er
by prog
ramm
in
g S
S
P
C
ON
2<
3>
(R
C
E
N
=
1
)
PEN b
it
=
1
wr
it
te
n
h
e
re
Da
ta
sh
ifte
d
in
o
n
fa
llin
g
e
d
g
e
o
f CL
K
Cle
a
re
d
in
so
ft
wa
re
st
a
rt X
M
IT
SE
N =
0
SSPO
V
SDA =
0
, S
C
L =
1
w
h
ile
CPU
(SSP
ST
A
T
<0
>)
ACK
La
st b
it
is sh
ifted
into
S
S
P
S
R
and
c
o
n
te
n
ts
a
re
u
n
lo
a
d
e
d
i
n
to
S
SPBUF
Cle
a
re
d
in
so
ft
wa
re
Cle
a
re
d
in
so
ft
wa
re
Se
t SSP
IF
in
te
rr
u
p
t
a
t en
d o
f r
e
cei
v
e
Se
t P
b
it
(SSPST
A
T
<4
>)
a
n
d
SSPI
F
Cle
a
re
d
in
sof
twar
e
ACK f
ro
m
m
a
s
te
r
Se
t
S
SPI
F a
t e
n
d
Se
t SSPI
F in
te
rr
u
p
t
at e
n
d
of
A
c
know
le
dg
e
seq
uen
ce
Se
t S
SPI
F
in
te
rr
u
p
t
at
end
of
A
ckno
w
-
le
d
ge sequ
en
ce
of
r
e
ceive
S
e
t A
C
K
E
N
, star
t A
ckno
w
le
d
ge s
equ
enc
e,
SSPO
V is
s
e
t b
e
c
a
u
s
e
SSPBUF
i
s
st
ill f
u
ll
SDA =
A
C
KDT =
1
RCEN cle
a
re
d
aut
oma
ti
c
al
ly
RCEN =
1
, st
ar
t
ne
xt r
e
ceive
W
rit
e
to
SSP
CO
N2
<4
>
to
st
a
rt
A
c
know
le
dg
e se
que
nce
,
SDA = ACKDT (
SSPCO
N
2
<
5
>
)
=
0
RCE
N
cle
a
re
d
a
u
to
m
a
tica
lly
re
s
p
o
n
d
s
t
o
SSPI
F
ACKEN
be
gi
n S
tar
t
co
ndi
ti
o
n
Cle
a
re
d
in
so
ft
wa
re
SD
A
=
A
C
KD
T =
0
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