ATMEGA32A_14 Datasheet, PDF (34/336 Pages) ATMEL Corporation – 8-bit Microcontroller with 32KBytes In-System Programmable Flash

details on which pins are enabled. If the input buffer is enabled and the input signal is left floating or have an analog
signal level close to V_CC/2, the input buffer will use excessive power.
10.8.7 JTAG Interface and On-chip Debug System
• If the On-chip debug system is enabled by the OCDEN Fuse and the chip enter Power down or Power save
sleep mode, the main clock source remains enabled. In these sleep modes, this will contribute significantly to
the total current consumption. There are three alternative ways to avoid this:
• Disable OCDEN Fuse.
• Disable JTAGEN Fuse.
• Write one to the JTD bit in MCUCSR.
The TDO pin is left floating when the JTAG interface is enabled while the JTAG TAP controller is not shifting data.
If the hardware connected to the TDO pin does not pull up the logic level, power consumption will increase. Note
that the TDI pin for the next device in the scan chain contains a pull-up that avoids this problem. Writing the JTD bit
in the MCUCSR register to one or leaving the JTAG fuse unprogrammed disables the JTAG interface.
ATmega32A [DATASHEET] 34
Atmel-8155D-AVR-ATmega32A-Datasheet_02/2014