NOVA electronics Inc. MCX514 -
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3.4.6 Check Available Space of Pre-buffer
MCX514 has 8 stages of pre-buffer for continuous interpolation. In bit pattern interpolation, it can store 8 stages of 16 bit pattern
data for each of all interpolation axes, that is, 16 × 8 = 128 bits. When the user performs interpolation over 128 bits, the user must
check the free space of pre-buffer during interpolation. The 4 bits of D12
～
D15 in RR0 register displays this stack counter value
of pre-buffer. When the value of 4 bits is 0, it indicates an empty state, and when it is 8, it indicates a full state and cannot write
BP data anymore. When bit pattern interpolation command is written, the stack counter is counted up by 1 and interpolation
driving starts. When output of 16 bits is finished, the stack counter is counted dow n by 1.
D11 bit (CNEXT ) of RR0 register notifies the writable state of next data for continuous interpolation. After interpolation driving
starts, CNEXT bit becomes 1 while the stack counter of pre-buffer is from 1 to 7. And during 1 of this bit, the host CPU
determines that it is possible to write next data.
RR0
D15
D14
D13
D12
D11
D10
D9
D8
D7
D6
D5
D4
D3
D2
D1
D0
H
L
HSTC0
HSTC2
HSTC3
HSTC1
CNEXT
Writable state of next data for interpolation
Interpolation Pre-buffer
stack counter
3.4.7 Interruption of Interpolation Driving
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Interruption by stop command
When instant or decelerating stop command is written to the main axis that performs bit pattern interpolation, interpolation driving
stops.
The stack counter of pre-buffer becomes 0 forcibly, and bit pattern data stacked in pre-buffer will be invalid.
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Interruption by hardware limit or software limit
During interpolation driving, when hardware or software limit of any axis becomes active, interpolation driving stops.
In bit pattern interpolation, even hardware or software limit of or – direction becomes active, interpolation driving may
stop. So please note that the user cannot escape from the limit area in bit pattern interpolation.
