4/21

16-BIT TIMING OPERATIONS USING ST7262 OR ST7263B MCUs

Figure 4. Input Capture Configuration

Figure 5 shows the steps that have to be followed to successfully measure the length of a

pulse in 16-bit accuracy.

Figure 5. Input Capture Sequence

1.1.2.2 Example of input capture interrupt routine

.Inp_Cap_Routine

;

Btjt ARTICCSR,#0,Flag1

; Test If is ICAP(1 Or 2)

.Flag2 Ld A , ARTICR2

; Latch the Input Cap Reg into

Ld IcapReg2 , A; IcapReg2

Ld A , ARTICCSR

; Clear Interrupt

ARTIC1

ARTIC2

External Signal

ST7262

Input capture interrupt

No

YES

ICAP1

ICAP2

- Configure Time clock frequency

- Select edge sensitivity on ICAP pins

- Cascade PWMART & TBU

- Store the TBU counter Value

(Compensated value) in PulseStartHR

- Store the ICRx Value in PulseStartLR

- Store the TBU counter Value

(Compensated value) in PulseEndHR

- Store the ICRx Value in PulseEndLR

ICAP1 Or ICAP2

1