Renesas Hitachi H8S/2191, Hardware Manual

Page: 393 / 1065

Rev. 2.0, 11/00, page 366 of 1037
17.2.5 Timer Control/Status Register X (TCSRX)
0
0
1
0
2
0
3
0
4
0
5
0
6
0
7
R/W R/(W)
*
ICFB
0
R/(W)
*
ICFA
R/(W)
*
ICFD
R/(W)
*
ICFC
R/(W)
*
OCFB
R/(W)
*
OCFA CCLRA
R/(W)
*
OVF
Note:
*
Only 0 can be written to clear the flag for Bits 7 to 1.
Bit :
Initial value :
R/W :
The TCSRX is an 8-bit register which works to select counter clearing timing and to control
respective interrupt requesting signals. The TCSRX is initialized to H'00 when reset or under
the standby mode, watch mode, subsleep mode, module stop mode or subactive mode.
Meanwhile, as for the timing, see section 17.3, Operation.
The FTIA through FTID pins are for fixed inputs inside the LSI under the low power
consumption mode excluding the sleep mode. Consequently, when such shifts as "active mode
→
low power consumption mode
→
active mode" are made, wrong edges may be detected
depending on the pin status or on the type of the detecting edge.
To avoid such error, clear the interrupt requesting flag once immediately after shifting to the
active mode from the low power consumption mode.
Bit 7: Input Capture Flag A (ICFA)
This is a status flag indicating the fact that the value of the FRC has been transferred to the
ICRA by the input capture signals.
When the BUFEA of the TCRX is being set to 1, the ICFA indicates the status that the FRC
value has been transferred to the ICRA by the input capture signals and that the ICRA value
before being updated has been transferred to the ICRC.
This flag should be cleared by use of of the software. Such setting should only be made by use
of the hardware. It is not possible to make this setting using a software.
Bit 7
ICFA Description
0 [Clearing conditions] (Initial value)
When 0 is written into the ICFA after reading the ICFA under the setting of ICFA = 1
1 [Setting conditions]
When the value of the FRC has been transferred to the ICRA by the input capture
signals