MC9S08JM16CGTE FREESCALE [Freescale Semiconductor, Inc], MC9S08JM16CGTE Datasheet - Page 314

• Manufacturer Part Number: MC9S08JM16CGTE
• Description: Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Universal Serial Bus Device Controller (S08USBV1)
17.4.1.5
The on-chip 3.3 V regulator provides a stable power source to power the USB internal transceiver and
provide for the termination of an internal or external pullup resistor. When the on-chip regulator is enabled,
it requires a voltage supply input in the range from 3.9 V to 5.5 V, and the voltage regulator output will be
in the range of 3.0 V to 3.6 V.
With a dedicated on-chip USB 3.3 V regulator and a separate power supply for the MCU, the MCU and
USB can operate at different voltages (See the USB electricals regarding the USB voltage regulator
electrical characteristics). When the on-chip 3.3 V regulator is disabled, a 3.3 V source must be provided
through the V
must not fall below the input voltage at the V
The 3.3 V regulator has 3 modes including:
17.4.1.6
The pullup resistor on the USBDP line required for full-speed operation by the USB Specification Rev. 2.0
can be internal or external to the MCU, depending on the application requirements. An on-chip pullup
resistor, implemented as specified in the USB 2.0 resistor ECN, is optionally available via firmware
configuration. Alternatively, this on-chip pullup resistor can be disabled, and the USB module can be
configured to use an external pullup resistor for the USBDP line instead. If using an external pullup resistor
on the USBDP line, the resistor must comply with the requirements in the USB 2.0 resistor ECN found at
http://www.usb.org.
The USBPU bit in the USBCTL0 register can be used to indicate if the pullup resistor is internal or external
to the MCU. If USBPU is clear, the internal pullup resistor on USBDP is disabled, and an external USBDP
pullup can be used. When using an external USBDP pullup, if the voltage regulator is enabled, the V
voltage output can be used with the USBDP pullup. While the use of the internal USBDP pullup resistor
is generally recommended, the figure below shows the USBDP pullup resistor configuration for a USB
device using an external resistor tied to V
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Active mode — This mode is entered when USB is active. Current requirement is sufficient to
power the transceiver and the USBDP pullup resistor.
Standby — The voltage regulator standby mode is entered automatically when the USB device is
in suspend mode. When the USB device is forced into suspend mode by the USB bus, the firmware
must configure the MCU for stop3 mode. In standby mode, the requirement is to maintain the
USBDP pin voltage at 3.0 V to 3.6 V, with a 900 Ω (worst-case) pullup.
Power off — This mode is entered anytime when stop2 or stop1 is entered or when the voltage
regulator is disabled.
USB On-Chip Voltage Regulator (VREG)
USB On-Chip USBDP Pullup Resistor
USB33
pin to power the USB transceiver. In this case, the power supply voltage to the MCU
MC9S08JM16 Series Data Sheet, Rev. 2
USB33
USB33
.
pin.
Freescale Semiconductor
USB33