195
CHAPTER 14 SERIAL INTERFACE SIO2
Preliminary User’s Manual U14581EJ3V0UM00
Cautions
1.
Bits 5 and 6 must be set to 0.
2.
While a serial transfer operation is enabled (CSIE2 = 1), be sure to stop the serial transfer
operation once before changing the values of bits other than CSIE2 to different data.
3.
When operation is disabled (CSIE2 = 0) during a serial transfer operation, the operation
will be sopped immediately. At this time, even if operation is enabled again (CSIE2 =
1) after it was once stopped, the operation will not start. To resume operation, set
operation enable (CSIE2 = 1) and then execute an access that will be the start trigger
of each transfer operation mode.
4.
Changing CSIE2 and other bits at the same time is prohibited. After clearing CSIE2 to
0, change the other bits.
Remark
f
X
: Main system clock oscillation frequency
(2) Communication operations
Data is transmitted/received in 8-bit units. 8-bit data is transmitted/received bit by bit in synchronization with the
serial clock.
Two transfer modes are provided for the 3-wire serial I/O mode: transmit/receive mode and receive-only mode.
After setting each operation mode using the serial operation mode register (CSIM2), transmit/receive operation
is started by performing an operation that will be the start trigger.
(3) Transfer start
A serial transfer starts when the following conditions have been satisfied.
•
Receive-only mode
When CSIE2 = 1 and MODE2 = 1, transfer starts when writing to SIO2.
•
Transmit/receive mode
When CSIE2 = 1 and MODE2 = 0, transfer starts when reading from SIO2.
Caution
After data has been written to SIO2, transfer will not start even if the CSIE2 bit value is set
to “1”.
Completion of an 8-bit transfer automatically stops the serial transfer operation and sets a serial transfer
completion flag.
Содержание mPD780851
Страница 2: ...2 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 8: ...8 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 12: ...12 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 26: ...26 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 46: ...46 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 74: ...74 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 90: ...90 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 100: ...100 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 136: ...136 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 142: ...142 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 186: ...186 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 222: ...222 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 230: ...230 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 240: ...240 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 262: ...262 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 296: ...296 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 304: ...304 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...
Страница 314: ...314 Preliminary User s Manual U14581EJ3V0UM00 MEMO ...