Rev. 7/15/2004
Copyright 2004 Sipex Corporation
APPLICATION NOTE
Processors in the Motorola MPC850 PowerQUICCTM family support one USB host port at a
12Mbit/sec data rate. They require an external USB transceiver, such as the
SP5301
, to
provide the analog interface to the Universal Serial Bus.
Motorola
MPC850
PowerQUICC
12Mbps
USB
Host
Controller
48MHz Ref. Clock
/OE
SUSPND
VM
VP
RCV
GND
VMO
SPEED
D-
D+
VPO
Vcc
SIPEX
SP5301
USBOE# (14)
USBRXM (10)
USBRXD (15)
USBRXP (11)
USBTXN (6)
USBTXP (7)
Vcc =
+3.3V
GND
D-
D+
V_BUS
V_BUS =
+5V
USB
Connector
Vcc =
+3.3V
Not shown:
0.1uF Bypass capacitor on Vcc
Float RERR and RSE0 (No Connect)
22
ohm
1.5K
RERR
RSE0
NC
NC
The USB controller on the MPC850 uses six signals. Additional signals such as SUSPEND and
SPEED can be driven using general purpose outputs if desired.
Signal
MPC
Dir Signal
SP5301
Function
USBTXN
VMO
USBTXP
VPO
Data outputs from Host, Inputs to Transceiver,
Driven onto D- and D+
USBOE#
OE#
Output Enable, controls SP5301 transmit or receive
USBRXD
RCV
Differential
Receive
USBRXP
VP
USBRXN
VM
Single Ended Receive. Gated version of D+ and D-. Used to
detect Single-ended Zero (EOF and Reset)
SUSP
Drive high to put SP5301 into low power state
SPEED
Drive low to adjust driver slew rate for Low Speed (1.5Mbps)
RERR
Outputs high if D+ and D- are 11 (illegal state).
Leave unconnected if not used
Optional
Signals
RSE0
Outputs high if D+ and D- are 00 (SE0).
Leave unconnected if not used
Connecting SP5301 to MPC850 PowerQUICCTM
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