Rainbow Electronics ATAR862-3 - Manual (Page 39)

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ATAR862-3
4556B–4BMCU–02/03
Port 6 Data Register (P6DAT) Primary register address: "6"hex
Port 6 Control Register (P6CR) Auxiliary register address: "6"hex
P6xM2, P6xM1 – Port 6x Interrupt mode/direction code
Universal Timer/Counter/
Communication Module
(UTCM) The Universal Timer/counter/Communication Module (UTCM) consists of three timers
(Timer 1,Timer 2, Timer 3) and a Synchronous Serial Interface (SSI).
• Timer 1 is an interval timer that can be used to generate periodical interrupts and as
prescaler for Timer 2, Timer 3, the serial interface and the watchdog function.
• Timer 2 is an 8/12-bit timer with an external clock input (T2I) and an output (T2O).
• Timer 3 is an 8-bit timer/counter with its own input (T3I) and output (T3O).
• The SSI operates as two wire serial interface or as shift register for modulation and
demodulation. The modulator and demodulator units work together with the timers
and shift the data bits into or out of the shift register.
There is a multitude of modes in which the timers and the serial interface can work
together.
Bit 3 Bit 2 Bit 1 Bit 0
P6DAT3 – – P6DAT0 Reset value: 1xx1b
Bit 3 Bit 2 Bit 1 Bit 0
P63M2 P63M1 P60M2 P60M0 Reset value: 1111b
Auxiliary Address: "6"hex Write Cycle
Code
3 2 1 0 Function
Code
3 2 1 0 Function
x x 1 1 BP60 in input mode 1 1 x x BP63 in input mode
x x 1 0 BP60 in output mode 1 0 x x BP63 in output mode
x x 0 x
BP60 enable alternate port
function (T3O for Timer 3) 0 x x x BP63 enable alternate port
function (T3I for Timer 3)