Atmel AT91EB55, Руководство пользователя

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AT91EB55 Evaluation Board User Guide 4-1
Rev. 1709C–ATARM–28-Apr-05
Section 4
Circuit Description
4.1 AT91M55800A
Processor
Figure 6-1 in “Appendix B – Schematics” shows the AT91M55800A. The footprint is for
a 176-pin TQFP package.
Strap CB15 enables the user to choose between the standard ICE debug mode and the
JTAG boundary scan mode of operation.
The operating mode is defined by the state of the JTAGSEL input detected at reset.
Jumper JP5 can be removed by the user to allow measurement of the current demand
by the whole microcontroller (V
DDIO
and V
DDCORE
). Jumper JP8 can be removed to mea-
sure the core microcontroller consumption (V
DDCORE
). See Figure 6-8. in “Appendix B –
Schematics.”
Jumper JP9 can be removed by the user to allow measurement of the current demand
by the APMC and RTC microcontroller modules (V
DDBU
). See Figure 6-8. in “Appendix B
– Schematics.”
4.2 Expansion
Connectors and
JTAG Interface
The two expansion connectors (I/O expansion connector and EBI expansion connector)
and the JTAG Interface are described below.
The I/O and EBI expansion connectors pin-outs and positions are compatible with the
other evaluation boards (except for the I/O expansion connector pin-out and position of
the EB40) so that users can connect their prototype daughter boards to any of these
evaluation boards. For the I/O expansion connector, rows A and B are position and
pinout compatible.
4.2.1 I/O Expansion
Connector The I/O expansion connector makes the general purpose I/O (GPIO) lines, VCC3V3 and
Ground available to the user. Configuration straps CB2, CB3, CB4, CB5, CB6, CB13,
CB14 and CB17 are used to select between the I/O lines being used by the evaluation
board or by the user via the I/O expansion connector. The connector is not fitted at the
factory; however, the user can fit any 32 x 3 connector on a 0.1" (2.54 mm) pitch.
4.2.2 EBI Expansion
Connector The schematic illustrated in Figure 6-4 in "Appendix B - Schematics" also shows the Bus
expansion connector, which, like the I/O expansion connector, is not fitted at the factory.
The user can fit any 32 x 2 connector on a 0.1" (2.54 mm) pitch to gain access to the
data, address, chip select, read/write, oscillator output and wait request pins. VCC3V3
and Ground are also available on this connector. Configuration strap CB1, when open,
allows the user to connect the EBI expansion connector to the MPI expansion connector
of an AT91EB63 evaluation board without fearing any conflict problem.