1 Alternatives to the SDRAM Interface

The following sections describe the microcontroller, memory, and microprocessor (MPU) alternatives to address the requirement of external SDRAM.

MCU Alternatives

The superset of devices in the MCU families, provided in the following table, have comparable or compatible features that can be considered as alternatives to the SDRAM interface on the SAM E70/S70/V70/V71 family of devices.

Table 1-1. MCU Family Devices
SI No	MCU Family	Core	SRAM	Flash	Processor Speed	Additional Memory Options	Suggested Parts	Parametric Search Link/Keyword	MPLAB Harmony v3 Usage Example(s)
1.	SAM E70/S70/V70/V71	Cortex®-M7	384 KB	2048 KB	300 MHz	QSPI ⁽²⁾, EBI⁽¹⁾	ATSAME70Q21 ATSAMS70Q21 ATSAMV70Q20 ATSAMV71Q21	SAME70 SAMS70 SAMV70 SAMV71	QSPI Memory usage example(s)
2.	PIC32MZ DA	MIPS32 microAptiv™	640 KB	2048 KB	200 MHz	DRAM (DDR2) ⁽³⁾ ,EBI⁽¹⁾	PIC32MZ2064DAS176 PIC32MZ2064DAR176	PIC32MZ DA	DDR Memory usage example(s)
3.	PIC32MZ EF	MIPS32 microAptiv	512 KB	2048 KB	200 MHz	SQI ⁽⁴⁾ ,EBI⁽¹⁾	PIC32MZ2048EFM144 PIC32MZ2048EFH144	PIC32MZ EF	SQI Memory usage example(s)
4.	PIC32CZ CA	Cortex®-M7	1MB/512KB	8MB/2MB	300MHz	SQI⁽⁵⁾, EBI⁽¹⁾	PIC32CZ8110CA90208 PIC32CZ8110CA80208 EA60E74A	PIC32CZ	SQI memory example
Note: Static Memory Controller (SMC) is part of the External Bus Interface (EBI) peripheral, providing a 16-bit interface with support for SRAM, PSRAM, PROM, EPROM, EEPROM, LCD module, NOR Flash, and NAND Flash. Quad I/O Serial Peripheral Interface (QSPI) enables interfacing up to 256 MB Flash with an eXecute-In-Place feature and RAM. Extended memory through the internal 32 MB DRAM (DDR2) or externally connected DRAM (DDR2) of 128 MB. The Serial Quad Interface (SQI) helps to communicate with memory devices, such as serial EEPROMs, serial Flash devices, and SPI RAM devices at 50 MHz rates. The SQI helps to communicate with memory devices, such as serial EEPROMs, serial Flash devices, and SPI RAM devices with interfacing upto 256MB/512MB.

MPU Alternatives

Microchip 32-bit MPUs are a natural extension to 32-bit MCUs and suitable for applications with large external memory requirements. They support multiple memory types, such as DDR2, DDR3, LPDDR2, LPDDR3, QSPI, and eMMC Flash.

The devices in the MPU family, as provided in the figure below, have comparable or compatible features that can be considered as an alternative to the SDRAM interface on the SAME70/S70/V70/V71 family of devices.

Table 1-2. MPU Family Devices
SI No	MPU Family	Core	SRAM	Flash	Processor Speed	Additional Memory Options	Packages	Suggested Parts	Parametric Search Link	MPLAB Harmony v3 Usage Example(s)
1.	SAMA5D2	Cortex-A5	N/A	N/A	500 MHz	DDR2 DDR3L LPDDR2 LPDDR3 QSPI eMMC	289-ball LFBGA, 14x14 mm², 1.4 mm thickness, 0.8 mm pitch	ATSAMA5D21	SAMA5D2	DDR2 usage example(s)^(1,2,3)
							256-ball TFBGA, 8x8 mm², 1.05 mm thickness, 0.4 mm pitch
							196-ball TFBGA, 11x11 mm², 0.75 mm thickness, 0.75 mm pitch
2.	SAM9X60	ARM926	64 KB	N/A	600 MHz	LPDDR DDR2 SDRAM LPSDR QSPI eMMC	228-ball TFBGA, 11x11 mm², 0.65mm pitch	SAM9X60	SAM9X60	DDR2 usage example(s)⁽³⁾
Note: The example link is for the SAM9X60 MPU. It can be easily adapted to the SAMA5D2 MPU family as MPLAB Harmony v3 supports the RAM FS (file system) for the SAMA5D2 family. SAMA5D2 Boot Process: microchipdeveloper.com/32mpu:boot-sama5d2-series. The above two families support Internal SDRAM. For additional information about MPUs that support other memory interfaces, refer to the www.microchip.com/en-us/products/microprocessors/32-bit-mpus.