DEMO9S08EL32 Freescale, DEMO9S08EL32 Datasheet - Page 9

• Manufacturer Part Number: DEMO9S08EL32
• Manufacturer: Freescale

Specifications of DEMO9S08EL32

• Lead Free Status / RoHS Status: Supplier Unconfirmed

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If powered from the PWR connector, the integrated BDM may still be used to develop and
debug application code. Alternately, the board may be powered from the integrated BDM
while the LIN bus is powered from the PWR connector.
VX_EN
The VX_EN option header is a 2-pin jumper that connects or disconnects input J1-1 directly to
the target board, +5V voltage rail. J1-3 is directly connected to the ground plane. Use of this
feature requires a regulated +5V input power source.
This power input is decoupled to
minimize noise but is not regulated. Care should be exercised when using this feature; no
protection is applied on this input and damage to the target board may result if over-driven.
Also, do not attempt to power the target board through this connector while also applying
power through the USB BDM or the PWR connector; damage to the board may result.
Power may also be sourced to off-board circuitry through the J1 connector. The current
supplied from the USB bus or the on-board regulator limits current available to external
circuitry. Excessive current drain may damage the target board, the host PC USB hub, or the
on-board regulator. Figure 3 below details the VX_EN header connections.
Figure 3: VX_EN Option Header
ON
OFF
1
2
Enabled
Disabled
VX_EN
CAUTION: Do not exceed available current supply from USB BDM or on-board regulator, when
sourcing power through connector J1 to external circuitry.
RESET SWITCH
The RESET switch applies an asynchronous RESET to the MCU. The RESET switch is
connected directly to the RESET* input on the MCU. Pressing the RESET switch applies a
low voltage level to the RESET* input. A pull-up bias resistor allows normal MCU operation.
Shunt capacitance ensures an adequate input pulse width.
LOW VOLTAGE RESET
The MC9S08EL32 utilizes an internal Low Voltage Detect (LVD) circuit. The LVD holds the
MCU in reset until applied voltage reaches an appropriate level. The LVD also protect against
under-voltage conditions. Consult the MC9S08EL32 reference manual for details LVD
operation.
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