
Serial interface control register
SIO0CR
7
6
5
4
3
2
1
0
(0x001F)
Bit Symbol
SIOEDG
SIOCKS
SIODIR
SIOS
SIOM
Read/Write
R/W
After reset
0
SIOEDG
Transfer edge selection
0
1
0: Receive data at a rising edge and transmit data at a falling edge
1: Transmit data at a rising edge and receive data at a falling edge
SIOCKS
Serial clock selection [Hz]
NORMAL1/2 or IDLE1/2 mode
SLOW1/2 or SLEEP1 mode
000
fcgck/29
-
001
fcgck/26
-
010
fcgck/25
-
011
fcgck/24
-
100
fcgck/23
-
101
fcgck/22
-
110
fcgck/2
fs/23
111
External clock input
SIODIR
Transfer format (MSB/LSB) selec-
tion
0
1
LSB first (transfer from bit 0)
MSB first (transfer from bit 7)
SIOS
Transfer operation start/stop in-
struction
0
1
0: Operation stop (reserved stop)
1: Operation start
SIOM
Transfer mode selection and
operation
00 Operation stop (forced stop)
01 8-bit transmit mode
10 8-bit receive mode
11 8-bit transmit and receive mode
Note 1: fcgck: Gear clock [Hz], fs: Low-frequency clock [Hz]
Note 2: After the operation is started by writing "1" to SIOS, writing to SIOEDG, SIOCKS and SIODIR is invalid until
SIO0SR<SIOF> becomes "0". (SIOEDG, SIOCKS and SIODIR can be changed at the same time as changing SIOS from
"0" to "1".)
Note 3: After the operation is started by writing "1" to SIOS, no values other than"00" can be written to SIOM until SIOF becomes
"0" (if a value from "01" to "11" is written to SIOM, it is ignored). The transfer mode cannot be changed during the operation.
Note 4: SIOS remains at "0", if "1" is written to SIOS when SIOM is "00" (operation stop).
Note 5: When SIO is used in SLOW1/2 or SLEEP1 mode, be sure to set SIOCKS to "110". If SIOCKS is set to any other value,
SIO will not operate. When SIO is used in SLOW1/2 or SLEEP1 mode, execute communications with SIOCKS="110" in
advance or change SIOCKS after SIO is stopped.
Note 6: When STOP, IDLE0 or SLEEP0 mode is activated, SIOM is automatically cleared to "00" and SIO stops the operation.
At the same time, SIOS is cleared to "0". However, the values set for SIOEDG, SIOCKS and SIODIR are maintained.
TMP89FH42
17. Synchronous Serial Interface (SIO)
17.2 Control
Page 254
RA001