Using the STK525
2-20
STK525 Hardware User Guide
7608A–AVR–04/06
2.7.3
EXP.CON 0 & EXP.CON 1 Connectors
Figure 2-19 . EXP.CON 0 and EXP.CON 1 Connectors
2.7.4
Main Clock from STK500
The AVR clock frequency (external) coming from STK500 (XT1/XT2) can also be
controlled from AVR Studio®.
“STKX1” and ”STKX2” jumpers should be closed
2.7.5
RESET from STK500
The AVR RESET coming from STK500 (NRST - EXP.CON 0) can also control the
STK525. STK525 is protected a12V RESET pulse (parallel programing not
allowed for AT90USBxxx on STK525) coming from STK500.
2.8
In-System Programming
2.8.1
Programming with USB bootloader: DFU (Device Firmware Upgrade)
AT90USBxxx part comes with a default factory pre-programmed USB bootloader
located in the on-chip boot section of the AT90USBxxx. This is the easiest and fastest
way to reprogram the device directly over the USB interface. The “Flip” PC side
application available for free on Atmel website offers a flexible and user friendly
interface to reprogram the application over the USB bus.
EXP. CON 1
GND
GND
1 2
n.c. (AUXI0)
n.c. (AUXO0)
3 4
n.c. (CT7)
n.c. (CT6)
5 6
n.c. (CT5)
n.c. (CT4)
7 8
n.c. (CT3)
n.c. (CT2)
9 10
n.c. (CT1)
n.c. (BSEL2)
11 12
n.c.
REF
13 14
NRST
PG2
15 16
PG1
PG0
17 18
GND
GND
19 20
PC7
PC6
23 24
VTG
VTG
21 22
PC5
PC4
25 26
PC3
PC2
27 28
PC1
PC0
29 30
PA7
PA6
31 32
PA5
PA4
33 34
PA3
PA2
35 36
PA1
PA0
37 38
GND
GND
39 40
GND
GND
1 2
n.c. (AUXI1)
n.c. (AUXO1)
3 4
n.c. (DATA7)
n.c. (DATA6)
5 6
n.c. (DATA5)
n.c. (DATA4)
7 8
n.c. (DATA3)
n.c. (DATA2)
9 10
n.c. (DATA1)
n.c. (DATA0)
11 12
n.c. (SI)
n.c. (SO)
13 14
n.c. (SCK)
n.c. (CS)
15 16
XT1
XT2
17 18
VTG
VTG
19 20
PB7
PB6
23 24
GND
GND
21 22
PB5
PB4
25 26
PB3
PB2
27 28
PB1
PB0
29 30
PD7
PD6
31 32
PD5
PD4
33 34
PD3
PD2
35 36
PD1
PD0
37 38
GND
GND
39 40
EXP. CON 0
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