TMP88CH40NG Datasheet, PDF (92/148 Pages) Toshiba Semiconductor – 8 Bit Microcontroller

11. Motor Control Circuit (PMD: Programmable motor
driver)
TMP88CH40NG
11.5.4 Protective Circuit
This circuit consists of an EMG protective circuit and overload protective circuit. These circuits are activated
by driving their respective port inputs active.
Overload protective input CL
Timer 1 interrupt INTTMR1
PWM synchronizing
clock PWM sync
Overload protective
interrupt INTCLM
Stop MDCNT
EMG control register
EMGCRB
EMGCRA
7 6, 5 4 3, 2, 1, 0 7, 6, 5, 4 − 2 1 0
2
4
4
2
EMG disable code register
CL detection
Under
prote-
ction
EMGREL
7, 6, 5, 4, 3, 2, 1, 0
8
MDOUT
A to 0
Set "0"
Reset
control
Overload
protective
control
EMG
protective
control
EMG
EMG input
INTEMG
EMG interrupt
u
u'
x
x'
v
v'
y
y'
w
w'
z
z'
Figure 11-13 Configuration of the Protective Circuit
a. EMG protective circuit
This protective circuit is used for emergency stop, when the EMG protective circuit is enabled.
When the signal on EMG input port goes active (negative edge triggered), the six ports are immedi-
ately disabled high-impedance against output and an EMG interrupt (INTEMG) is generated. The
EMG Control Register (EMGCRA) is used to set EMG protection. If the EMGCRA<EMGST>
shows the value “1” when read, it means that the EMG protective circuit is operating. To return from
the EMG protective state, reset the MDOUT Register bits A to 0 and set the EMGCRA<RTE> to 1.
Returning from the EMG protective state is effective when the EMG protective input has been
released back high. To disable the EMG function, set data “5AH“ and “A5H“sequentially in the
EMG disable Register (EMGREL) and reset the EMGCRA<EMGEN> to 0. When the EMG func-
tion is disabled, EMG interrupts (INTEMG) are not generated.
The EMG protective circuit is initially enabled. Before disabling it, fully study on adequacy.
b. Overload protective circuit
The overload protective circuit is set by using the EMG Control Registers (EMGCRA/B). To acti-
vate overload protection, set the EMGCRB<CLEN> to 1 to enable the overload protective circuit.
The circuit starts operating when the overload protective input is pulled low.
To return from overload state, there are three methods to use: return by a timer
(EMGCRB<RTTM1>), return by PWM sync (EMGCRB<RTPWM>), or return manually
(EMGCRB<RTCL>). These methods are usable when the overload protective input has been
released back high.
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