Rainbow Electronics ATAR862-3 - Manual (Page 63)

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ATAR862-3
4556B–4BMCU–02/03
Timer 3 Control Register 1
(T3C) Write Primary register address: "C"hex - Write
Timer 3 Status Register 1
(T3ST) Read Primary register address: "C"hex - Read
Note: The status bits T3C1, T3C2 and T3ED will be reset after a READ access to T3ST.
Timer 3 Clock Select Register
(T3CS) Address: "B"hex - Subaddress: "1"hex
Bit 3 Bit 2 Bit 1 Bit 0
Write T3EIM T3TOP T3TS T3R Reset value: 0000b
T3EIM T imer 3 E dge I nterrupt M ask
T3EIM = 0, disables the interrupt when an edge event for Timer 3 occurs (T3I)
T3EIM = 1, enables the interrupt when an edge event for Timer 3 occurs (T3I)
T3TOP T imer 3 T oggle O utput P reset T3TOP = 0, sets toggle output (M3) to "0"
T3TOP = 1, sets toggle output (M3) to "1"
Note: If T3R = 1, no output preset is possible
T3TS T imer 3 T oggle with S tart T3TS = 0, Timer 3 output is not toggled during the start
T3TS = 1, Timer 3 output is toggled if started with T3R
T3R T imer 3 R un T3R = 0, Timer 3 stop and reset
T3R = 1, Timer 3 run
Bit 3 Bit 2 Bit 1 Bit 0
Read - - - T3ED T3C2 T3C1 Reset value: x000b
T3ED T imer 3 E dge D etect
This bit will be set by the edge-detect logic of Timer 3 input (T3I)
T3C2 T imer 3 C ompare 2
This bit will be set when a match occurs between Counter 3 and T3CO2
T3C1 T imer 3 C ompare 1
This bit will be set when a match occurs between Counter 3 and T3CO1
Bit 3 Bit 2 Bit 1 Bit 0
T3CS T3E1 T3E0 T3CS1 T3CS0 Reset value: 1111b
T3E1 T imer 3 E dge select bit 1 T3E1 T3E0 Timer 3 Input Edge Select (T3I)
T3E0 T imer 3 E dge select bit 0 1 1 –
1 0 Positive edge at T3I pin
0 1 Negative edge at T3I pin
0 0 Each edge at T3I pin