Block Diagram - Freescale Semiconductor MCF52277 Reference Manual

Universal Serial Bus Interface – On-The-Go Module
For OTG operations, external circuitry is required to manage the host negotiation protocol (HNP) and
session request protocol (SRP). External ICs that are capable of providing the OTG VBUS with support
for HNP and SRP, as well as support for programmable pullup and pulldown resistors on the USB DP and
DM lines are available from various manufacturers.
The on-chip FS/LS transceiver also includes a programmable pullup resistor on USB DP. This pullup is
configurable via the CCM. Also, configurable 50 kΩ pulldown resistors are available on the USB_DP and
USB_DM signals of the on-chip transceiver. See
(MISCCR)," for more information. The primary function of the transceiver is the physical signal
conditioning of the external USB DP and DM cable signals for a USB 2.0 network. Several USB system
elements are not supported on the device as they are available via standard products from various
manufacturers.
20.1.2

Block Diagram

Figure 20-1 shows the USB On-The-Go interface using the on-chip full-speed/low-speed transceiver.
Configuration
Figure 20-1. USB On-The-Go with on-chip FS/LS Transceiver Interface Block Diagram
20.1.3 Features
The USB On-The-Go module includes these features:
• Complies with USB specification rev 2.0
• USB host mode
20-2
ColdFire Processor
USB On-The-Go
Transceiver
Chip
Module
MCF52277 Reference Manual, Rev. 1
Section 9.3.4, "Miscellaneous Control Register
Board Interconnect
USBD_DP
FS/LS
USBD_DM
OTG
Control
Status
Interrupt
SCL/SDA
I2C
Master
USB
Mini-AB
Connector
DP
DM
Optional
VBUS
VBUS
Supply
ID
Required
OTG
Charge
Pump+
Res.
Charge Pump
Capacitor
Freescale Semiconductor