AT91SAM7XC128B-CU Atmel, AT91SAM7XC128B-CU Datasheet - Page 27
![MCU ARM 128K HS FLASH 100-TFBGA](/photos/6/89/68968/313-100-cbga_sml.jpg)
AT91SAM7XC128B-CU
Manufacturer Part Number
AT91SAM7XC128B-CU
Description
MCU ARM 128K HS FLASH 100-TFBGA
Manufacturer
Atmel
Series
AT91SAMr
Datasheet
1.AT91SAM7XC128B-CU.pdf
(47 pages)
Specifications of AT91SAM7XC128B-CU
Core Processor
ARM7
Core Size
16/32-Bit
Speed
55MHz
Connectivity
CAN, Ethernet, I²C, SPI, SSC, UART/USART, USB
Peripherals
Brown-out Detect/Reset, DMA, POR, PWM, WDT
Number Of I /o
62
Program Memory Size
128KB (128K x 8)
Program Memory Type
FLASH
Ram Size
32K x 8
Voltage - Supply (vcc/vdd)
1.65 V ~ 1.95 V
Data Converters
A/D 8x10b
Oscillator Type
Internal
Operating Temperature
-40°C ~ 85°C
Package / Case
100-TFBGA
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Eeprom Size
-
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9.1
9.1.1
6209DS–ATARM–17-Feb-09
Reset Controller
Brownout Detector and Power-on Reset
The AT91SAM7XC512/256/128 embeds one brownout detection circuit and a power-on reset
cell. The power-on reset is supplied with and monitors VDDCORE.
Both signals are provided to the Flash to prevent any code corruption during power-up or power-
down sequences or if brownouts occur on the power supplies.
The power-on reset cell has a limited-accuracy threshold at around 1.5V. Its output remains low
during power-up until VDDCORE goes over this voltage level. This signal goes to the reset con-
troller and allows a full re-initialization of the device.
The brownout detector monitors the VDDCORE and VDDFLASH levels during operation by
comparing them to a fixed trigger level. It secures system operations in the most difficult environ-
ments and prevents code corruption in case of brownout on the VDDCORE or VDDFLASH.
When the brownout detector is enabled and VDDCORE decreases to a value below the trigger
level (Vbot18-, defined as Vbot18 - hyst/2), the brownout output is immediately activated.
When VDDCORE increases above the trigger level (Vbot18+, defined as Vbot18 + hyst/2), the
reset is released. The brownout detector only detects a drop if the voltage on VDDCORE stays
below the threshold voltage for longer than about 1µs.
The VDDCORE threshold voltage has a hysteresis of about 50 mV, to ensure spike free brown-
out detection. The typical value of the brownout detector threshold is 1.68V with an accuracy of
± 2% and is factory calibrated.
When the brownout detector is enabled and VDDFLASH decreases to a value below the trigger
level (Vbot33-, defined as Vbot33 - hyst/2), the brownout output is immediately activated.
When VDDFLASH increases above the trigger level (Vbot33+, defined as Vbot33 + hyst/2), the
reset is released. The brownout detector only detects a drop if the voltage on VDDCORE stays
below the threshold voltage for longer than about 1µs.
The VDDFLASH threshold voltage has a hysteresis of about 50 mV, to ensure spike free brown-
out detection. The typical value of the brownout detector threshold is 2.80V with an accuracy of
± 3.5% and is factory calibrated.
The brownout detector is low-power, as it consumes less than 28 µA static current. However, it
can be deactivated to save its static current. In this case, it consumes less than 1µA. The deac-
tivation is configured through the GPNVM bit 0 of the Flash.
• Based on one power-on reset cell and one brownout detector
• Status of the last reset, either Power-up Reset, Software Reset, User Reset, Watchdog
• Controls the internal resets and the NRST pin output
• Allows to shape a signal on the NRST line, guaranteeing that the length of the pulse meets
Reset, Brownout Reset
any requirement.
AT91SAM7XC512/256/128 Preliminary
27