Table of Contents
12. Synchronous Serial Interface (SIO)
12.2 Control
12.2 Control
The serial interface is controlled by SIO control registers (SIOCR1/SIOCR2). The serial interface status can be
determined by reading SIO status register (SIOSR).
The transmit and receive data buffer is controlled by the SIOCR2. The data buffer is assigned to address
0F90H to 0F97H for SIO in the DBR area, and can continuously transfer up to 8 words (bytes or nibbles) at one time.
When the specified number of words has been transferred, a buffer empty (in the transmit mode) or a buffer full (in
the receive mode or transmit/receive mode) interrupt (INTSIO) is generated.
When the internal clock is used as the serial clock in the 8-bit receive mode and the 8-bit transmit/receive mode, a
fixed interval wait can be applied to the serial clock for each word transferred. Four different wait times can be
selected with SIOCR2.
SIO Control Register 1
SIOCR1
(0F98H)
SIOS
SIOINH
SIOM
Note 1: fc; High-frequency clock [Hz], fs; Low-frequency clock [Hz]
Note 2: Set SIOS to "0" and SIOINH to "1" when setting the transfer mode or serial clock.
Note 3: SIOCR1 is write-only register, which cannot access any of in read-modify-write instruction such as bit operate, etc.
SIO Control Register 2
SIOCR2
(0F99H)
7
6
5
SIOS
SIOINH
Indicate transfer start / stop
Continue / abort transfer
Transfer mode select
SCK
Serial clock select
7
6
5
4
3
2
SIOM
0:
Stop
1:
Start
0:
Continuously transfer
1:
Abort transfer (Automatically cleared after abort)
000:
8-bit transmit mode
010:
4-bit transmit mode
100:
8-bit transmit / receive mode
101:
8-bit receive mode
110:
4-bit receive mode
Except the above: Reserved
NORMAL1/2, IDLE1/2 mode
DV7CK = 0
13
000
fc/2
8
001
fc/2
7
010
fc/2
6
011
fc/2
5
100
fc/2
4
101
fc/2
110
111
External clock ( Input from SCK pin )
4
3
2
WAIT
Page 132
TMP86PM29BUG
1
0
SCK
(Initial value: 0000 0000)
SLOW1/2
SLEEP1/2
DV7CK = 1
5
fs/2
8
fc/2
7
fc/2
6
fc/2
5
fc/2
4
fc/2
Reserved
1
0
BUF
(Initial value: ***0 0000)
Write
only
mode
5
fs/2
-
-
Write
only
-
-
-
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