For Atmel AT91SAM9261S — Debug Unit
Simulation support for this peripheral or feature is comprised of:
- Dialog boxes which display and allow you to change peripheral configuration.
These simulation capabilities are described below.
Debug Unit Dialog
The Debug Unit Dialog configures built-in Debug Unit.
DBGU_CR (Debug Control Register) displays the combined
control information for the following:
- RXEN (Receiver Enable) enables the receiver.
- TXEN (Transmitter Enable) enables the transmitter.
- RXDIS (Receiver Disable) disables the receiver.
TXDIS (Transmitter Disable) disables the
- RSTRX (Reset Receiver) resets the receiver.
- RSTTX (Reset Transmitter) resets the transmitter.
RSTSTA (Reset Status Bits) resets the Parity Error
(PARE), Framing Error (FRAME), Overrun Error (OVRE) and Break
Received (RXBRK) status bits.
DBGU_MR (Mode Register) contains the following Mode
CHMODE (Channel Mode) selects normal, loopback, echo or
remote loopback pin configurations.
PAR (Parity Type) selects the generation of even, odd or
no parity bits, mark or space, or multi-drop mode.
DBGU_BRGR (Baud Rate Generator Register) holds the
CD (Clock Divisor) contains the value divided into the
clock that determines the baud rate.
- Baudrate displays the calculated baud rate.
Receiver & Transmitter
DBGU_RHR (Receiver Holding Register) contains the
RXCHR (Received Character) holds the last character
DBGU_THR (Transmitter Holding Register) contains the
TXCHR (Character to be Transmitted) holds the next
character to be transmitted.
Interrupt Mask & Status
DBGU_IMR (Interrupt Mask Register) holds the masking
bits for all of the internal peripheral interrupts.
DBGU_SR (Channel Status Register) hold the following
PARE (Parity Error) set if the controller detects at
least 1 false parity bit since the last Reset Status Bits command
FRAME (Framing Error) set if the controller detects a
framing error since the last Reset Status Bits command
OVRE (Overrun Error) set if the controller detects an
overrun condition since the last Reset Status Bits command
ENDTX (End of Transmitter Transfer) is set if the End of
Transmitter signal is active.
ENDRX (End of Receiver Transfer) is set if the End of
Receiver signal is active.
TXRDY (Transmitter Ready) set if the transmit hold
register (DBGU_THR) is empty and there is no break request
RXRDY (Receiver Ready) set when the USART receives at
least 1 character and the receiver hold register (DBGU_RHR) is not
COMMTX (Debug Communication Channel Write Status) is set
if the Debug Communication Channel Write signal is active.
COMMRX (Debug Communication Channel Read Status) is set
if the Debug Communication Channel Read signal is active.
RXBUFF (Receive Buffer Full) is set if the Buffer Full
signal from the PDC is active.
TXBUFF (Transmit Buffer Full) is set if the Buffer Empty
signal from the PDC is active.
TXEMPTY (Transmitter Empty) set if there are no
characters in the transmitter hold register.
DBGU_CDIR (Chip ID Register) contains the chip
identification information: processor type, NV memory size,
Internal RAM size, NV memory type and chip architecture.
EXT (Extension Flag) is set when an extended chip ID
Chip ID Extension
DBGU_EXID (Extension ID) displays the chip extension
DBGU_FNR (Force NTRST Register) hold the following bit
FNTRST (Force NTRST) is set to hols the NTRST of the ARM
processor's TAP controller low. If reset, the TAP controller is
driven by the ICE_NRESET signal.