Toshiba 6F3B0253 - Manual (Page 267)

6F3B0253
Basic Hardware and Function
265
8. Special I/O Functions
8.3.3 Quadrature 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
µ
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