VII - 17Chapter 7 16-bit Timer16-bit Event Count7-4-2 Setup ExampleEvent Count Setup Example (Timer 7)If the falling edge of the TM7IO input pin signal is detected 5 times with using timer 7, an interrupt isgenerated. An example setup procedure, with a description of each step is shown below.(1) Set the TM7EN flag of the timer 7 mode register1 (TM7MD1) to "0" to stop timer 7 counting.(2) Set the P1DIR4 flag of the port 1 directioncontrol register (P1DIR) to "0" to set P14 pin toinput mode.If it needs, pull-up resistor should be added.(3) Set the TM7BCR flag of the timer 7 moderegister 2 (TM7MD2) to "1" to select thecompare match as a clear source of binarycounter.(4) Select the TM7IO input as a clock source by theTM7CK1-0 flag of the TM7MD1 register. Also,select 1/1(no division) as a count clock sourceby the TM7PS1-0 flag.(5) Set the interrupt generation cycle to the timer 7preset register 1 (TM7PR1). The set valueshould be 4, because the counting is 5 times.At that time, the same value is loaded to thetimer 7 compare register 1 (TM7OC1), and thetimer 7 binary counter (TM7BC) is initialized tox'0000'.Setup Procedure(1) Stop the counter.TM7MD1 (x'3F78')bp4 : TM7EN = 0(2) Set the special function pin to inputmode.P1DIR (x'3F31')bp4 : P1DIR4 = 0(3) Select the condition for timer clear.TM7MD2 (x'3F79')bp5 : TM7BCR = 1(4) Select the count clock source.TM7MD1 (x'3F78')bp1-0 : TM7CK1-0 = 10bp3-2 : TM7PS1-0 = 00(5) Set the interrupt generation cycle.TM7PR1 (x'3F75', x'3F74')=x'0004'Description[ Chapter 4 I/O Ports ]
