3 transfer mode, Toshiba – Toshiba TMP87CP24AF User Manual
Page 86
Attention! The text in this document has been recognized automatically. To view the original document, you can use the "Original mode".
TOSHIBA
TMP87CM24A/P24A
(3)
Number of Words to Transfer
Up to
8
words consisting of 4 bits of data (4-bit serial transfer) or
8
bits (
8
-bit serial transfer) of data
can be transferred continuously. The number of words to be transferred is loaded to BUF.
An
INTSIO
interrupt
is
generated
when
the
specified
number
of
words
has
been
transferred.
If
the
number
of
words
is
to
be
changed
during
transfer,
the
serial
interface
must
be
stopped
before
making
the
change.
The
number
of
words
can
be
changed
during
automatic-wait
operation
of
an
internal clock. In this case, the serial interface is not required to be stopped.
2.9.3 Transfer Mode
SIOM (bits 5 to 3 in SI01CR1/SI02CR1) is used to select the transmit, receive, ortransmit/receive mode.
(1) 4-Bit and 8-Bit Transmit
Modes
In
these
modes,
the
SI01CR1/SI02CR1
is
set
to
the
transmit
mode
and
then
the
data
to
be
transmitted
first
are
written
to
the
data
buffer
registers
(DBR).
After
the
data
are
written,
the
transmission
is
started
by
setting
SIOS
to
"
1
".
The
data
are
then
output
sequentially
to the
SO
pin
in
synchronous
with
the
serial
clock,
starting
with
the
least
significant
bit
(LSB).
As
soon
as
the
LSB
has
been
output,
the
data
are
transferred
from
the
data
buffer
register
to
the
shift
register.
When
the
final
data
bit
has
been
transferred
and
the
data
buffer
register
is
empty,
an
INTSIO
(buffer
empty)
interrupt is generated to request the next transmitted data.
When
the
internal
clock
is
used,
the
serial
clock
will
stop
and
an
automatic-wait
will
be
initiated
if
the
next
transmitted
data
are
not
loaded
to
the
data
buffer
register
by
the
time
the
number
of
data
words
specified
with
the
BUF
has
been
transmitted.
Writing
even
one
word
of
data
cancels
the
automatic-wait;
therefore,
when
transmitting
two
or
more
words,
always
write
the
next
word
before transmission of the previous word is completed.
Note: Automatic-waits are also canceled by writing to a DBR not being used as a transmit data
buffer
register;
therefore,
during
SIO
do
not
use
such
DBR
for
other
applications.
For
example, when 3 words are transmitted, do not use the DBR of the remained 5 words.
3
-
24-86
2002
-
10-03