Connection Of Signals To Mcu - Motorola M68HC08 Manual

DRM046 — Rev 0
MOTOROLA
Freescale Semiconductor, Inc.
Table 5-6. Connection of Signals to MCU
Signal
Hall Sensor A
Hall Sensor B
Hall Sensor C
Phase A Top
Phase A Bottom
Phase B Top
Phase A Bottom
Phase C Top
Phase C Bottom
PWM / Enable
Fault Input
DC-Bus Voltage
Speed Pot
Run / Stop Switch
As can be seen, all signals of MC68HC908QY4 are used.
Six outputs, PTB0-PTB5 are used for control of the power MOSFETs.
They are wired through NAND's with open collector and corresponding
pull-ups. The PWM is generated on TCH0, and the individual pins PTB0
- PTB5 enable the PWM to appear at the corresponding input of the
3-phase gate driver.
When power is applied or removed, it is important that the top and
bottom output transistors in the same phase are not turned on
simultaneously. Since logic states are not always defined during
power-up, it is important to ensure that all power transistors remain off
when the controller's supply voltage is below its normal operating level.
Since the inputs of the 3-phase gate driver IR2132 have negative logic,
the pull-up resistors R35-R40 disable the driver outputs. Also, pull down
Hardware Design
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Detailed Design Description
MC6+8HC908QY4 Pins
PTB7
PTB6
PTA1 / TCH1
PTB0
PTB1
PTB2
PTB3
PTB4
PTB5
PTA0 / TCH0
PTA2 / IRQ
PTA5 / AD3
PTA4 / AD2
PTA3
Designer Reference Manual
Hardware Design
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