Fujitsu FR81S User Manual
CHAPTER 40: MULTI-FUNCTION SERIAL INTERFACE
8. Operation of I2C
FUJITSU SEMICONDUCTOR LIMITED
CHAPTER : MULTI-FUNCTION SERIAL INTERFACE
FUJITSU SEMICONDUCTOR CONFIDENTIAL
328
8.2.5. Serial Timer Operations
Serial timer can be used as a timer feature.
Activating Serial Timer
Activating a serial timer consists of two types: Setting "1" to the serial timer enable bit (SACSR:TMRE);
Activating by external trigger.
⋅
Activating with serial timer enable bit (SACSR:TMRE)
When external trigger enable bit (SACSR : TRGE) is set to "0", setting "1" to serial timer enable bit
(SACSR:TMRE) will activate the serial timer and the serial timer register (STMR) will start counting
from "0".
Figure 8-5 Activating with Serial Timer Enable Bit
(STMCR="10", SACSR:TRGE="0")
10
0
1
2
・・・
9
10
1
0
STMR
STMCR
TINT
TMRE
Serial timer activation
⋅
Activating with external trigger
While external trigger enable bit (SACSR : TRGE) is set to "1", the serial timer will be activated and the
serial timer register (STMR) will start counting from "0" when serial timer enable bit (SACSR:TMRE) is
set to "1" and an edge of the external trigger which is set by the trigger selection bit (TRG1 and TRG0) is
detected.
Figure 8-6 Activating with External Trigger
(STMCR="10", SACSR:TRGE="1", TRG1="0", TRG0="1")
10
0
1
2
・・・
9
10
1
0
STMR
STMCR
TINT
TMRE
External trigger
Serial timer activation
MB91520 Series
MN705-00010-1v0-E
1641