Kontron AM4011, Руководство пользователя

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AM4011 Configuration
ID 1022-1626, Rev. 1.0 Page 4 - 17
P R E L I M I N A R Y
4.4.15 Delay Timer Control /Status Register
The delay timer enables the user to realize short, reliable delay times. It runs by default and
does not start again on its own. It can be restarted at anytime by writing anything other than a
’0’ to the Delay Timer Control/Status Register. The hardware delay timer provides a set of out-
puts for defined elapsed time periods. The timer outputs reflected in the Delay Timer Control/
Status Register are set consecutively and remain set until the next restart is triggered again.
Since the timer width and thus the availability of outputs varies over different implementations,
it is necessary to be able to determine the timer capability. Therefore, writing a ’0’ to the Delay
Timer Control/Status Register followed by reading indicates the timer capability (not the timer
outputs). For example, writing 0x00 and then reading 0xFF results in an 8-bit wide timer regis-
ter. This status register mode can be switched off to normal timer operation by writing anything
other than a ’0’ to this register.
Table 4-22: Delay Timer Control / Status Register
REGISTER NAME DELAY TIMER CONTROL / STATUS REGISTER
ADDRESS 0x28F
BIT NAME DESCRIPTION
RESET
VALUE
ACCESS
7-0 DTC Delay Timer Control
The hardware delay timer is operated via one simple 8-bit control/
status register. During normal operation, each of the 8 bits reflects a
timer output which means defined elapsed time period after the last
restart according to the following bit mapping:
DTC[7:0] Value Accuracy
Bit 7: 1 ms < + 0.04%
Bit 6: 500 µs < + 0.08%
Bit 5: 250 µs < + 0.16%
Bit 4: 100 µs < + 0.4%
Bit 3: 50 µs < + 0.8%
Bit 2: 10 µs < + 4%
Bit 1: 5 µs < + 8%
Bit 0: 1 µs < + 40%
0x00 R/W