MB90F654A FUJITSU [Fujitsu Component Limited.], MB90F654A Datasheet - Page 38

• Manufacturer Part Number: MB90F654A
• Description: 16-bit Proprietary Microcontroller
• Manufacturer: FUJITSU [Fujitsu Component Limited.]

38
MB90650A Series
3. I/O Extended Serial Interface
(1) Register Details
I/O extended serial interface consists of an 8-bit serial I/O interface that can perform clock synchronous data
transfer. Either LSB-first or MSB-first data transfer can be selected.
The following two serial I/O operation modes are available.
• Internal shift clock mode: Data transfer is synchronized with the internal clock.
• External shift clock mode: Data transfer is synchronized with the clock input from the external pin (SCK). By
This register controls the transfer operation mode of the serial I/O. The following describes the function of each bit.
bit 3: Serial mode selection bit (MODE)
The bit is initialized to “0” by a reset. The bit is readable and writable. Set to “1” when using the intelligent I/O
bit 2: Transfer direction selection bit (BDS: Bit Direction Select)
Serial data register 0, 1 (SDR0, SDR1)
Serial mode control status register 0, 1 (SMCS0, SMCS1)
*1: Only “0” can be written.
*2: Only “1” can be written. Reading always returns “0”.
manipulating the general-purpose port that shares the external pin (SCK), this
mode also enables the data transfer operation to be driven by CPU instructions.
This bit selects the conditions for starting operation from the halted state. Changing the mode during
operation is prohibited
Selects as follows at the time of serial data input and output whether the data are to be transferred in
the order from LSB to MSB or vice versa.
MODE
MODE
0
1
0
1
Address : 000025
Address : 000024
Address : 000026
R/W
—
R
X
LSB-first [Initial value]
MSB-first
: Readable and writable
: Read only
: Unused
: Indeterminate
Start when STRT is set to “1”. [Initial value]
Start on reading from or writing to the serial data register.
000029
000028
00002A
H
H
H
H
H
H
SMD2 SMD1 SMD0
bit 15
R/W
R/W
bit 7
bit 7
D7
—
—
bit 14
R/W
bit 6
R/W
bit 6
D6
—
—
bit 13
R/W
R/W
bit 5
bit 5
D5
—
—
Operation
Operation
bit 12
R/W
SIE
bit 4
bit 4
R/W
D4
—
—
MODE BDS
R/W
bit 11
R/W
R/W
SIR
bit 3
bit 3
D3
*1
BUSY STOP STRT
bit 10
R/W
bit 2
R/W
bit 2
D2
R
SOE
R/W
R/W
bit 9
bit 1
bit 1
R/W
D1
SCOE
R/W
R/W
bit 8
bit 0
bit 0
R/W
D0
*2
- - - - 0 0 0 0
0 0 0 0 0 0 1 0
XXXXXXXX
Initial value
Initial value
Initial value
B
B
B