Using the STK594 Top Module
FPSLIC STK594 User Guide 2-5
2819A–FPSLI–07/02
2.7 Two-Wire Serial
Interface (TWSI)
The AT94K device includes dedicated I/O pins for the TWSI rather than sharing with the
general purpose I/O pins.
Figure 2-8 shows the pinout of a header for the dedicated TWSI pins.
Figure2-8.
TWSI Header
2.7.1 Description of
Configuration
Memory Pins
An AT17LV010-10CC 1-Mbit Configuration Memory is included on the STK594 for sup-
plying the AT94K FPSLIC device with its con figuration data, as well as for non-volatile
data storage. The configurator is a high-density EEPROM with a TWSI interface. A
detailed datasheetof the Configuration Memory can be obtained from theAtmel web
site.
The configurator can be connected to the I/O pins of the embedded AVR microcontrol-
ler. The 4-pin header marked
CONFIG
can be used for connecting the TWSI interface of
the configurator to the I/O pins ofthe target AVR microcontroller.Two-wire cables are
included with the STK500 for connecting the configurator to the I/O pins.
Figure 2-9 shows the pinout of a header for the Configuration Memory pins.
Figure2-9.
Configuration Memory Header
2.8 External
Interrupts
Unlike traditional AVR microcontrollers, the AT94K device provides the option of having
separate I/O pins for the External Interrupts rather than sharing with the general purpose
I/O pins.
Figure 2-10 shows the pinout of a header for the dedicated External Interrupt pins.
Figure 2-10.
External Interrupt Header
SCLSDA
1 2
TWSI
cSCL
N/C
cSDA
cSER_EN
1 2
CONFIG
INTP1
INTP3
INTP0
INTP2
1 2
EXT