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TMP89FM42
RA001
13.4.6.3 Register buffer configuration
(1)
Temporary buffer
The TMP89FM42 contains an 8-bit temporary buffer. When a write instruction is executed on
TA0DRAL (TA0DRBL), 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
(TA0DRBH), the set value is stored into the double buffer or TA0DRAH (TA0DRBH). At the same
time, the set value in the temporary buffer is stored into the double buffer or TA0DRAL
(TA0DRBL). (This structure is designed to enable the set values of the lower-level register and the
higher-level register simultaneously.) Therefore, when setting data to TA0DRA (TA0DRB), be sure
to write the data into TA0DRAL and TA0DRAH (TA0DRBL and TA0DRBH) in this order.
See Figure 13-1 for the temporary buffer configuration.
(2)
Double buffer
In the TMP89FM42, the double buffer can be used by setting TA0CR<TA0DBF>. Setting
TA0CR<TA0DBF> to "0" disables the double buffer. Setting TA0CR<TA0DBF> to "1" enables the
double buffer.
See Figure 13-1 for the double buffer configuration.
- When the double buffer is enabled
When a write instruction is executed on TA0DRAH (TA0DRBH) during the timer opera-
tion, the set value is first stored into the double buffer, and TA0DRAH/L are not updated
immediately. TA0DRAH/L (TA0DRBH/L) compare the last set values to the counter value.
If a match is detected, an INTTCA0 interrupt request is generated and the double buffer set
value is stored into TA0DRAH/L (TA0DRBH/L). Subsequently, the match detection is exe-
cuted using a new set value.
When a read instruction is executed on TA0DRAH/L (TA0DRBH/L), the double buffer
value (the last set value) is read, not the TA0DRAH/L (TA0DRBH/L) values (the current
effective values).
When a write instruction is executed on TA0DRAH/L (TA0DRBH/L) while the timer is
stopped, the set value is immediately stored into both the double buffer and TA0DRAH/L
(TA0DRBH/L).
- When the double buffer is disabled
When a write instruction is executed on TA0DRAH (TA0DRBH) during the timer opera-
tion, the set value is immediately stored in TA0DRAH/L (TA0DRBH/L). Subsequently, the
match detection is executed using a new set value.
If the values set to TA0DRAH/L (TA0DRBH/L) are smaller than the up counter value, the
up counter overflows and the match detection is executed using a new set value. As a result,
the output pulse width may be longer than the set time. If that is a problem, enable the double
buffer.
When a write instruction is executed on TA0DRAH/L (TA0DRBH/L) while the timer is
stopped, the set value is immediately stored into TA0DRAH/L (TA0DRBH/L).
Содержание TLCS-870/C1 Series
Страница 1: ...8 Bit Microcontroller TLCS 870 C1 Series TMP89FM42 查询TMP89FM42供应商 捷多邦 专业PCB打样工厂 24小时加急出货 ...
Страница 3: ...Revision History Date Revision 2007 10 25 1 First Release 2007 11 3 2 Contents Revised ...
Страница 4: ......
Страница 14: ......
Страница 18: ...1 3 Block Diagram TMP89FM42 1 3 Block Diagram Figure 1 2 Block Diagram ...
Страница 22: ...1 4 Pin Names and Functions TMP89FM42 ...
Страница 60: ...2 CPU Core 2 5 Revision History TMP89FM42 ...
Страница 76: ...3 Interrupt Control Circuit 3 8 Revision History TMP89FM42 ...
Страница 86: ...4 External Interrupt control circuit 4 3 Function TMP89FM42 ...
Страница 102: ...7 Voltage Detection Circuit 7 5 Revision History TMP89FM42 ...
Страница 126: ...8 I O Ports 8 3 I O Port Registers TMP89FM42 Note 2 i 0 to 1 ...
Страница 136: ...8 I O Ports 8 5 Revision History TMP89FM42 ...
Страница 142: ...9 Special Function Registers 9 3 SFR3 0x0E40 to 0x0EFF TMP89FM42 ...
Страница 146: ...10 Low Power Consumption Function for Peripherals TMP89FM42 ...
Страница 149: ...TMP89FM42 11 3 Revision History Rev Description RA001 Deleted SLEEP2 description ...
Страница 150: ...11 Divider Output DVO 11 3 Revision History TMP89FM42 ...
Страница 220: ...15 Real Time Clock RTC 15 4 Real Time Clock Operation TMP89FM42 ...
Страница 250: ...16 Asynchronous Serial Interface UART 16 15 Revision History TMP89FM42 ...
Страница 302: ...18 Serial Bus Interface SBI 18 7 Revision History TMP89FM42 ...
Страница 336: ...21 Flash Memory 21 4 Toggle Bit D6 TMP89FM42 Note 1 Make sure that you set the C register to 0x00 LD FLSCR2 0xD5 ...
Страница 338: ...21 Flash Memory 21 4 Toggle Bit D6 TMP89FM42 ...
Страница 384: ...22 Serial PROM Mode 22 15 Revision History TMP89FM42 ...
Страница 388: ...24 Input Output Circuit 24 1 Control Pins TMP89FM42 ...
Страница 404: ...25 Electrical Characteristics 25 11 Revision History TMP89FM42 ...
Страница 406: ...26 Package Dimensions TMP89FM42 ...
Страница 408: ......