Distributor of Equinox Technologies: Excellent Integrated System Limited
Datasheet of ISPNANO S3 KIT - ISP PORTABLE PROGRAMMER
Contact us: [email protected] Website: www.integrated-circuit.com
ISPnano Series Programmer - User Manual – V1.11 – 12
th
May 2011
87
1.3 Atmel AVR microcontroller - SPI connections
Most Atmel AVR microcontrollers use the standard “SPI” pins for In-System Programming – see
diagram (a) below. However, certain ATmega devices actually use the UART pins (RXD / TXD) for In-
System Programming – see diagram (b) below. Please refer to Application Note AN101 for detailed
instructions of how to program an Atmel AVR microcontroller via the SPI interface.
(a) Standard AVR “SPI” programming pin-out
MOSI
SCK
MISO
Vcc
Vss
RESET
PROG_RESET
PROG_MOSI
PROG_SCK
PROG_MISO
Atmel
ATmega
AVR
Microcontroller
(Standard
pin-out)
PROG_VCC
PROG_GND
Reset
Circuit
S
P
I
P
O
R
T
(b) AVR “UART” programming pin-out
RXD
SCK
TXD
Vcc
Vss
RESET
PROG_RESET
PROG_MOSI
PROG_SCK
PROG_MISO
Atmel
ATmega
AVR
Microcontroller
(UART
pin-out)
PROG_VCC
PROG_GND
Reset
Circuit
S
P
I
P
O
R
T
The table below details the connections for programming Atmel AVR microcontrollers via the SPI
Interface.
Pin
No
Programmer
Pin name
Programmer
Input /
Output
Connect to
pin on
Target System
Notes
1 + 2
TARGET_VCC
P
TARGET_VCC
Target VCC
3 + 4
TARGET_EXT_VCC P
See notes.
Target External VCC
5 + 6
PROG_GND
P
Signal GROUND
(0V)
Signal Ground Connection
12
Programmer I/O3
I/O
SPI - SCK
SPI - Serial Clock Signal
13
Programmer I/O2
I/O
SPI - MISO
SPI – Master In Slave Out
14
Programmer I/O1
I/O
SPI - MOSI
SPI – Master Out Slave In
16
PROG_RESET
O
RESET
Target RESET control pin
O - Output from programmer to Target Device
I - Input to programmer from Target Device
P - Passive e.g. GROUND and power rails
N/C - Not connected
104 / 135
104 / 135
