ATSTK503 Atmel, ATSTK503 Datasheet - Page 12

• Manufacturer Part Number: ATSTK503
• Description: STARTER KIT AVR EXP MODULE 100P
• Manufacturer: Atmel

Specifications of ATSTK503

• Accessory Type: STK500 Expansion Module
• Processor To Be Evaluated: Atmegaxxxx
• Data Bus Width: 8 bit
• Interface Type: JTAG
• For Use With/related Products: 100-pin megaAVR Devices
• For Use With: ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Only SRAM chips with center power pins can be used. See the Appendix for
details.
Address latch
The data bus and the low byte of the address bus is multiplexed on PORTA. The
ALE signal indicates when the address is present. This low byte must be stored
by a latch until the memory access cycle is completed.
The STK503's a latch is connected to the ALE signal. The latched low byte of the
address is routed to the SRAM footprint, and is also accessible on the connector
marked A[7:0].
High address jumpers
Some or all of the highest eight address pins on the External Memory Interface
can be disabled and used as general I/O. This feature is supported on STK503
by mounting the appropriate RAM HIGH ADDRESS jumpers. The lines which are
disconnected from the SRAM footprint are pulled low so the address lines of the
SRAM isn't floating.
12