SERIAL COMMUNICATION INTERFACE (SCI)
MOTOROLA
PORT C
6 - 47
R8
FE
PE
OR
IDLE
1
TDRE
TRNE
1.
THE RECEIVER IS IDLE UNTIL A CHARA
CTER IS RECEIVED IN
THE D
A
T
A SHIFT REGISTER.
RXD
2.
TRANSFERRING
THE RECEIVED CHARA
CTER INT
O SRX SETS RDRF IN
THE SSR.
765432
1
0
RDRF
X:$FFF1
ST
A
TUS REGISTER (SSR)
(READ ONL
Y)
3.
IF RIE = 1 IN SCR,
THEN AN INTERR
UPT IS GENERA
TED
.
SCI RECEIVE D
A
T
A
RECEIVE
INTERR
UPT
SER
VICE
R
OUTINE
P:$0014
INTERR
UPT
VECT
OR
T
ABLE
4.
THE RECEIVE INTERR
UPT SER
VICE R
OUTINE READS
THE RECEIVED CHARA
CTER.
5.
READING SRX CLEARS RDRF IN
THE SSR.
Figure 6-23 SCI Character Reception
23
16
15
8
7
0
X:$FFF6
X:$FFF5
X:$FFF4
SRX
SRX
SRX
F
re
e
sc
a
le
S
e
m
ic
o
n
d
u
c
to
r,
I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
c
.
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