Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 11 MOTOR CONTROL FUNCTION
R01UH0042EJ0500 Rev.5.00 Page 601 of 1513
Aug 12, 2011
(4) Automatic dead-time width narrowing function (TAB1OPT2.TAB1DTM bit = 1)
The dead-time width can be automatically narrowed in the vicinity of 0% output or 100% output by setting the
TAB1OPT2.TAB1DTM bit to 1.
By setting the TAB1DTM bit to 1, the dead-time counter is not cleared, but starts down counting if the TOAB1m
(internal signal) output of timer AB changes during dead-time counting.
The following timing chart shows the operation of the dead-time counter when the TAB1DTM bit is set to 1.
Figure 11-13. Operation of Dead-Time Counter m (1)
(a) In vicinity of 0% output
(TAB1CCRm register = i ≥ M + 1 − a/2, TAB1CCR0 register = M, TAB1DTC register = a)
Dead-time counter m starts counting down
Negative-phase wave output width: (M + 1 − i) × 4
(e.g., output width is 4 where TAB1CCRm = M)
16-bit
counter
0000H
TOAB1m signal
(internal signal)
Dead-time
counter m
TOAB1Tm
pin output
TOAB1Bm
pin output
000H
(b) In vicinity of 100% output (TAB1CCRm register = i ≤ a/2, TAB1CCR0 register = M, TAB1DTC register = a)
Dead-time counter m starts counting down
Positive-phase wave output width: (M + 1 − i) × 2 − (i × 2)
(e.g., output width is M × 2 − 2 where TAB1CCRm = 0001H)
Note
16-bit
counter
0000H
TOAB1m signal
(internal signal)
Dead-time
counter m
TOAB1Tm
pin output
TOAB1Bm
pin output
000H
Note The output width of the first wave differs from that of the second and subsequent waves immediately
after the TAB1CTL0.TAB1CE bit has been set. The first wave is shorter than the second wave because
the dead time is fully counted.
Remark m = 1 to 3