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6174B–ATARM–07-Nov-05
AT91FR40162S Preliminary
6.5
Emulation Functions
6.5.1
Tri-state Mode
The AT91FR40162S microcontroller provides a tri-state mode, which is used for debug pur-
poses. This enables the connection of an emulator probe to an application board without having
to desolder the device from the target board. In tri-state mode, all the output pin drivers of the
AT91R40008 microcontroller are disabled.
In tri-state mode, direct access to the Flash via external pins is provided. This enables produc-
tion Flash programming using classical Flash programmers prior to board mounting.
To enter tri-state mode, the NTRI pin must be held low during the last 10 clock cycles before the
rising edge of NRST. For normal operation, the NTRI pin must be held high during reset by a
resistor of up to 400 k
Ω
.
NTRI is multiplexed with I/O line P21 and USART1 serial data transmit line TXD1.
6.5.2
JTAG/ICE Debug
ARM-standard embedded In-circuit Emulation is supported via the JTAG/ICE port. The pins TDI,
TDO, TCK and TMS are dedicated to this debug function and can be connected to a host com-
puter via the external ICE interface. In ICE Debug Mode, the ARM7TDMI core responds with a
non-JTAG chip ID that identifies the microcontroller. This is not fully IEEE1149.1 compliant.