tmp89fm42l TOSHIBA Semiconductor CORPORATION, tmp89fm42l Datasheet - Page 170

• Manufacturer Part Number: tmp89fm42l
• Description: 8 Bit Microcontroller Tlcs-870/c1 Series
• Manufacturer: TOSHIBA Semiconductor CORPORATION

13.4
Timer Function
RB002
13.4.1.4
(1)
(2)
Register buffer configuration
TA0DRAL, the data is first stored into this temporary buffer, whether the double buffer is enabled or
disabled. Subsequently, when a write instruction is executed on TA0DRAH, the set value is stored into
the double buffer or TA0DRAH. At the same time, the set value in the temporary buffer is stored into
the double buffer or TA0DRAL. (This structure is designed to enable the set values of the lower-level
and higher-level registers simultaneously.) Therefore, when setting data to TA0DRA, be sure to write
the data into TA0DRAL and TA0DRAH in this order.
TA0CR<TA0DBF> to "0" disables the double buffer. Setting TA0CR<TA0DBF> to "1" enables the
double buffer.
The TMP89FM42L contains an 8-bit temporary buffer. When a write instruction is executed on
See Figure 13-1 for the temporary buffer configuration.
In the TMP89FM42L, the double buffer can be used by setting TA0CR<TA0DBF>. Setting
See Figure 13-1 for the double buffer configuration.
Temporary buffer
Double buffer
-
-
When the double buffer is enabled
is first stored into the double buffer, and TA0DRAH/L are not updated immediately.
TA0DRAH/L compare the up counter value to the last set values. If the values are matched,
an INTTCA0 interrupt request is generated and the double buffer set value is stored in
TA0DRAH/L. Subsequently, the match detection is executed using a new set value.
value) is read, rather than the TA0DRAH/L values (the current effective values).
value is immediately stored into both the double buffer and TA0DRAH/L.
When the double buffer is disabled
is immediately stored into TA0DRAH/L. Subsequently, the match detection is executed using
a new set value.
is executed using a new set value after the up counter overflows. Therefore, the interrupt request
interval may be longer than the selected time. If that is a problem, enable the double buffer.
value is immediately stored into TA0DRAH/L.
When a write instruction is executed on TA0DRAH during the timer operation, the set value
When a read instruction is executed on TA0DRAH/L, the double buffer value (the last set
When a write instruction is executed on TA0DRAH/L while the timer is stopped, the set
When a write instruction is executed on TA0DRAH during the timer operation, the set value
If the values set to TA0DRAH/L are smaller than the up counter value, the match detection
When a write instruction is executed on TA0DRAH/L while the timer is stopped, the set
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