SMART Embedded Computing MVME2502, Installation And User Manual

Page: 88 / 150

88 MVME2502 Installation and Use (6806800R96L)
Functional Description
Functional Description
4.11.1 Tsi148 VME Controller
The VMEbus interface for the MVME2502 is provided by the Tsi148 VMEbus controller.
The Tsi148 provides the required VME, VME extensions, and 2eSST functions. TI
SN74VMEH22501transceivers are used to buffer the VME signals between the Tsi148 and
the VME backplane. Refer to the
Tsi148 user's manual
for additional details and/or
programming information.
4.12 USB
The MVME2502 processor implements a dual-role (DR) USB 2.0 compliant serial interface
engine. DC power to the front panel USB port is supplied using a USB power switch which
provides soft-start, current limiting, over current detection, and power enable for port 1.
4.13 I
2
C Devices
The MVME2502 utilizes two I
2
C ports provided by the board's processor. The I
2
C bus is a
two-wire, serial data (SDA) and serial clock (SCL), synchronous, multi-master bi-directional
serial bus that allows data exchange between this device and other devices such as VPD,
SPD, EEPROM, RTC, temperature sensor, RTM, XMC, and IDT clocking.
The user can configure the RTM I
2
C adders and should be aware to avoid address
duplication. For more information on I
2
C bus device addressing, see
I
2
C Bus Device
Addressing on page 134
.