This presentation will focus on the 256 KB Flash version of the SAM3U4. There are also 128 KB (SAM3U2) and 64 KB (SAM3U1) versions available. The SAM3U4 is available in four different packages: 144-pin QFP and BGA versions are called SAM3U4E, and 100-pin QFP and BGA versions are called SAM3U4C. For worst case voltage, process and temperature, the SAM3U4 can run at up to 84 MHz. But if at least 1.8 V on the core power supply can be ensured, it is possible to run at up to 96 MHz. Shown on this slide is the block diagram of the 144-pin version of the SAM3U4. The four masters of the system are represented in green and the slaves in yellow. There are two masters from the core, which are the instruction/data master (I/D) and system bus master (S), the USB high-speed device master, the 4-channel central DMA master which is used to perform memory-to-memory transfers to the high-speed peripherals and the fifth master, which is the peripheral DMA used to perform memory-to-peripheral transfers without CPU intervention. These masters can be connected to up to ten different slaves thanks to the AHB matrix which is the same as can be found on the SAM9 products. So the interest of the AHB matrix is to perform transfers from different masters to different slaves at the same time. The SAM3U has two internal SRAM blocks, two internal Flash memories, an embedded ROM, the user interface of the high-speed USB device, the external bus interface to connect different external memories, a NAND Flash controller with its own internal 4 KB SRAM, and two separate peripheral bridges, one dedicated to the high-speed peripherals, which are the high-speed MCI, which is the controller to connect SDIOs, SDCards, as well as the high-speed SPI and SSC. The SPI is used to connect to the different SPI slaves and the SSC to the different I2S devices. The other bridge is connected to the other peripherals, such as the two-wire Interface, the controller to connect to the I2C devices. The SAM3U also has up to four USARTs, up to three 16-bit Timers, four different PWM channels, and up to eight 10-bit ADC channels and up to eight 12-bit ADC channels. These are the user peripherals. The backup unit on the chip embeds a Real-time clock (RTC) and Real-time timer (RTT), as well as general purpose registers and different oscillators. The backup unit can be powered independently from the rest of the chip through the backup pin. Finally, there are other peripherals such as Watchdog Timer, and a UART called DBGU on previous SAM7 products.