NT68P61A Datasheet, PDF (34/48 Pages) List of Unclassifed Manufacturers – 8-Bit Microcontroller for Monitor (24K OTP ROM Type)

polarity at the HALFHO output pin - '1' for
NT68P61A
positive polarity and '0' for negative polarity.
14. BASE TIMER (BT)
The Base Timer is an 8-bit counter whose clock source must be chosen with 1µs or 1ms by setting or clearing the TBS bit
('0' for 1µs and '1' for 1ms). The BT can be enabled/disabled by the ENBT bit in the BTCON register. When user clearing
this control bit to '0', the BT will start counting, otherwise setting this bit to '1' will stop the counting. After chip is reset, the
TBS and ENBT bits are set to '1' (the BT is disabled). BT, can be preset by writing BT7 - BT0 to the BT register (write
only) at any time and the BT will start count-up from preset value. When the value reaches FFH, it generates a timer
interrupt if the timer interrupt is enabled. When it reaches the maximum value of FFH, the base timer will wrap around and
begin counting at 00H. The timer interval can be within 256 ms maximum if set TBS to '1'. The timer interval can be within
256µs maximum if set TBS to '0'.
1 µs
0
1ms
1
TBS
BT7 BT6 BT5 BT4 BT3 BT2 BT1 BT0
TMR INT
Control bit description:
Addr. Register INIT
Bit7
Bit6
Bit5
Bit4
Bit3
Bit2
$0016
BT
00H
BT7
BT6
BT5
BT4
BT3
BT2
$0017 BT CON 03H
-
-
-
-
-
-
BT control register :
BT0 - BT7: Preloaded value of the base timer. The timer will count-up from this value.
BTCON control register:
ENBT : When clearing this bit, the base timer will be activated.
TBS: Select the input clock source of base timer - '1' for 1ms and '0' for 1µs.
Bit1
Bit0
BT1
BT0
W
TBS
ENBT W
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