Toshiba 6F3B0253 user manual Quadrature bi-pulse counter

6F3B0253

8. Special I/O Functions

8.3.3Quadrature bi-pulse counter

Function

This function counts up or down the quadrature bi-pulse (2-phase pulses whose phases are shifted 90° each other). Counts up when phase A precedes, and counts down when phase B precedes. Both rising and falling edges of each phase are counted. Consequently, 4 times count value against the pulse frequency is obtained.

Phase A

Phase B

Up count Down count

When the count value reaches the comparison value 1 (or 2), the I/O interrupt program #1 (or #2) is activated (if the interrupt enable flag for each is ON).

This counter operation is enabled while the soft-gate is ON. The count value is reset to 0 when the soft-gate is changed from ON to OFF. The count value is also reset to 0 when the reset input comes ON.

When the soft-gate is OFF, the count value can be changed by writing the data into the comparison value 1 (or 2) register and setting the count preset flag 1 (or 2) to ON. The comparison value 1 and 2 can be changed even when the soft-gate is ON.

The count value range is -2147483648 to 2147483647 (32-bit data).

Hardware condition

Phase A and phase B (X000 and X001)

ON/OFF pulse width: 100∝ s or more (max. 5KHz)

Reset input (X002)

ON/OFF duration: 2ms or more

Related registers

SW16: Function selection. Refer to section 8.1.

Function	Register/device	Remarks
Phase A	X000
Phase B	X001
Reset input	X002
Comparison value 1	SW19⋅SW18	Data range: -2147483648 to 2147483647
Comparison value 2	SW21⋅SW20
Count value	SW23⋅SW22
Soft-gate	S240	Operation is enabled when ON
Interrupt enable 1	S241	Interrupt 1 is enabled when ON
Count preset 1	S243	Used to preset the count value
Interrupt enable 2	S249	Interrupt 2 is enabled when ON
Count preset 2	S24B	Used to preset the count value

Basic Hardware and Function 265