ATSTK501 Atmel, ATSTK501 Datasheet - Page 15

• 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

2.9
2.10
AVR
®
STK501 User Guide
TOSC Switch
RS-232C Port
Figure 2-12. Enabling SRAM Interface for Devices in STK500
On the ATmega128(L) the TOSC1 and TOSC2 lines are shared with Port G (PG4 and
PG3). The TOSC switch select if the 32 kHz crystal, or the Port G connector pins should
be connected to the pins on the device.
Figure 2-13 shows a simplified block schematic on how this is implemented.
Note:
Figure 2-13. TOSC Block Schematic
The ATmega128(L) has an additional UART compared to the ATmega103(L). The RS-
232 port on the STK501 board has in addition to the RXD and TXD lines support for
RTS and CTS flow control. Figure 2-14 shows a simplified block schematic on how this
is implemented.
Note:
Port G is not available on the ATmega103(L), the switch will thus only select if
the 32 kHz crystal should be connected or not.
The UART in ATmega128(L) does not support hardware RTS or CTS control. If
such functionality is needed, it must be implemented in software.
PG3/TOSC2
PG4/TOSC1
AVR
TOSC
Switch
32 kHz
Using the STK501 Top Module
PG3
PG4
PORT G/AUX
Connector
To
2-9