tmp1940cyaf TOSHIBA Semiconductor CORPORATION, tmp1940cyaf Datasheet - Page 262

• Manufacturer Part Number: tmp1940cyaf
• Description: 32-bit Tx System Risc Tx19 Family
• Manufacturer: TOSHIBA Semiconductor CORPORATION

14.8 Clock-Synchronous 8-Bit SIO Mode Operation
14.8.1
Serial Clock
(1) Clock Source
programming of the SCK[2:0] field in the SBI0CR1.
SCK Output
SO Output
Writes of the
transmit data
The clock source for the SIO mode can be selected from internal and external clocks through the
Internal clocks
SCK pin. At the beginning of a transfer, the SCK clock will start out at logic high.
can not keep up with the serial clock rate, the SBI automatically inserts a wait period, as
shown below. During this period, the serial clock is temporarily stopped to suspend a shift
operation.
External clock (SBI0CR1.SCK[2:0] = 111)
from the SCK pin as a serial clock. For proper shift operations, the clock high width and the
clock low width must satisfy the following relationship.
One of the seven internal clocks can be used as a serial clock, which is driven onto the
If software is slow and the reading of the received data or the writing of the transmit data
If the SCK[2:0] field in the SBI0CR1 contains 111, the SBI uses an external clock supplied
SCK Pin
a
a
Figure 14.22 Maximum External Clock Frequency
1
0
t
SCKL
a
TMP1940CYAF-220
2
1
Figure 14.21 Automatic Wait Insertion
, t
a
SCKH
t
2
SCKL
3
a
5
Automatically inserted wait period
> 8/fsys
t
SCKH
a
7
6
a
8
7
b
b
1
0
b
1
2
c
b
4
TMP1940CYAF
b
6
5
b
7
6
b
8
7
c
1
0
c
2
1
c
3
2