ATSTK501 Atmel, ATSTK501 Datasheet - Page 14

• Manufacturer Part Number: ATSTK501
• Description: ADAPTER KIT FOR 64PIN AVR MCU
• Manufacturer: Atmel

Specifications of ATSTK501

• Accessory Type: STK500 Expansion Module
• Processor To Be Evaluated: ATmega103 and ATmega128
• Data Bus Width: 8 bit
• Interface Type: RS-232
• For Use With/related Products: 64-pin megaAVR Devices
• For Use With: ATADAPCAN01 - EXTENSION CAN ADD-ON TO STK500/1ATSTK500 - PROGRAMMER AVR STARTER KIT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: Q1167170; STK501; STK501

Using the STK501 Top Module
2.6
2.7
2.8
2-8
Ram High
Address
Jumpers
A[7:0] Connector
Using the SRAM
Interface with
AT90S/LS8515
and ATmega161
Figure 2-11. SRAMEN Connected to GND
When External Memory is enabled in an AVR, all Port C pins are by default used for the
high address byte. If the full 60 KB address space is not required to access the external
memory, some, or all, Port C pins can be released for normal port pin function as
described in the ATmega128(L) datasheet. AT90S/LS8515, ATmega103(L) and
ATmega161 do not have this feature, and all jumpers should be connected if using the
XRAM interface with these devices.
If some or all of the Port C pins are released for normal port pin functions, the corre-
sponding “RAM High Address” jumper should be removed to avoid any Port C activity to
reach the SRAM address pins thus corrupting the address.
If a jumper is removed, the corresponding address line will be pulled low giving a logic
zero on that address bit on the SRAM. See the block schematic on Figure 2-10.
The connector marked A[7:0] contains the 8 least-significant bits of the external SRAM
address bus. The purpose of the connector is to provide easy access to the address
bus. The 8 most significant bits can be found on the “Ram High Addresses” jumpers or
the Port C connector.
The connector is placed after the latch as shown in Figure 2-10.
This connector is handy when using the SRAM interface to interface external devices.
When using the SRAM interface with devices placed in the STK500 board, some addi-
tional straps are required. The reason is that the RD, WR, and ALE signals are not on
the same port pins for the AT90S8515/ATmega161(L) and ATmega103(L)/
ATmega128(L), so these signals must be routed manually using two of the 2-wire
cables.
Table 2-2. Signal Routing Required for AT90S8515A and ATmega161(L)
Connections
Write Signal WR
Read Signal RD
Address Latch Enable ALE
STK500
PD6
PD7
PE1
STK501
PG0
PG1
PG2
Description
Connect PD6:STK500 to PG0:STK501
Connect PD7:STK500 to PG1:STK501
Connect PE1:STK500 to PG2:STK501
AVR
®
STK501 User Guide