tmp88ch40img TOSHIBA Semiconductor CORPORATION, tmp88ch40img Datasheet - Page 122

• Manufacturer Part Number: tmp88ch40img
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

13.3 Serial clock
13. Synchronous Serial Interface (SIO)
13.3.1.1 Internal clock
13.3.1.2 External clock
SCK
pin (Input)
SCK
pin (output)
SO
pin (output)
Written transmit
data
SCK pin goes high when transfer starts.
cannot keep up with the serial clock rate, there is a wait function that automatically stops the serial clock
and holds the next shift operation until the read/write processing is completed.
should be set to input mode. To ensure shifting, a pulse width of more than 2
needed for the shift operation to execute certainly. Actually, there is necessary processing time for inter-
rupting, writing, and reading. The minimum pulse is determined by setting the mode and the program.
Any of six frequencies can be selected. The serial clock is output to the outside on the SCK pin. The
When data writing (in the transmit mode) or reading (in the receive mode or the transmit/receive mode)
Note: 1 Kbit = 1024 bit (fc = 20 MHz)
An external clock connected to the
Figure 13-3 Automatic Wait Function (at 4-bit transmit mode)
Table 13-1 Serial Clock Rate
SCK
000
001
010
100
101
011
110
111
t
SCKL
Figure 13-4 External clock pulse width
a
t
a
SCKH
0
a
1
External
a
Clock
fc/2
fc/2
fc/2
fc/2
fc/2
fc/2
2
-
13
8
7
6
5
4
SCK
Page 114
NORMAL, IDLE mode
pin is used as the serial clock. In this case, the
Automatically
wait function
a
3
t
SCKL
b
156.25 Kbps
312.50 Kbps
625.00 Kbps
125.00 Kbps
78.13 Kbps
Baud Rate
2.44 Kbps
, t
b
External
SCKH
0
-
> 2
b
1
4
/fc
c
b
2
b
4
3
/fc is required. This pulse is
c
0
TMP88CH40IMG
c
1
SCK
(P43) port