AT91SAM9XE128-QU Atmel, AT91SAM9XE128-QU Datasheet - Page 102

• Manufacturer Part Number: AT91SAM9XE128-QU
• Description: MCU ARM9 128K FLASH 208-PQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM9XE128-QU

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 180MHz
• Connectivity: EBI/EMI, Ethernet, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 96
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 40K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 4x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 208-MQFP, 208-PQFP
• Processor Series: AT91SAMx
• Core: ARM926EJ-S
• Data Bus Width: 32 bit
• Data Ram Size: 16 KB
• Interface Type: 2-Wire, EBI, I2S, SPI, USART
• Maximum Clock Frequency: 180 MHz
• Number Of Programmable I/os: 96
• Number Of Timers: 6
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: JTRACE-ARM-2M, KSK-AT91SAM9XE-PL, MDK-ARM, RL-ARM, ULINK2
• Development Tools By Supplier: AT91SAM-ICE, AT91-ISP, AT91SAM9XE-EK
• Minimum Operating Temperature: - 40 C
• On-chip Adc: 10 bit, 4 Channel
• For Use With: AT91SAM9XE-EK - KIT EVAL FOR AT91SAM9XEAT91SAM-ICE - EMULATOR FOR AT91 ARM7/ARM9
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

15.3.2
15.3.2.1
15.3.2.2
102
AT91SAM9XE128/256/512 Preliminary
NRST Manager
NRST Signal or Interrupt
NRST External Reset Control
These reset signals are asserted by the Reset Controller, either on external events or on soft-
ware action. The Reset State Manager controls the generation of reset signals and provides a
signal to the NRST Manager when an assertion of the NRST pin is required.
The NRST Manager shapes the NRST assertion during a programmable time, thus controlling
external device resets.
The startup counter waits for the complete crystal oscillator startup. The wait delay is given by
the crystal oscillator startup time maximum value that can be found in the section Crystal Oscil-
lator Characteristics in the Electrical Characteristics section of the product documentation.
The Reset Controller Mode Register (RSTC_MR), allowing the configuration of the Reset Con-
troller, is powered with VDDBU, so that its configuration is saved as long as VDDBU is on.
The NRST Manager samples the NRST input pin and drives this pin low when required by the
Reset State Manager.
Figure 15-2. NRST Manager
The NRST Manager samples the NRST pin at Slow Clock speed. When the line is detected low,
a User Reset is reported to the Reset State Manager.
However, the NRST Manager can be programmed to not trigger a reset when an assertion of
NRST occurs. Writing the bit URSTEN at 0 in RSTC_MR disables the User Reset trigger.
The level of the pin NRST can be read at any time in the bit NRSTL (NRST level) in RSTC_SR.
As soon as the pin NRST is asserted, the bit URSTS in RSTC_SR is set. This bit clears only
when RSTC_SR is read.
The Reset Controller can also be programmed to generate an interrupt instead of generating a
reset. To do so, the bit URSTIEN in RSTC_MR must be written at 1.
The Reset State Manager asserts the signal ext_nreset to assert the NRST pin. When this
occurs, the “nrst_out” signal is driven low by the NRST Manager for a time programmed by the
field ERSTL in RSTC_MR. This assertion duration, named EXTERNAL_RESET_LENGTH, lasts
NRST
Figure 15-2
RSTC_SR
nrst_out
URSTS
NRSTL
shows the block diagram of the NRST Manager.
External Reset Timer
RSTC_MR
RSTC_MR
ERSTL
URSTEN
RSTC_MR
URSTIEN
interrupt
sources
Other
user_reset
exter_nreset
6254C–ATARM–22-Jan-10
rstc_irq