Shenzhen ADA Electronics Co. Ltd. ADA789 用户手册
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6 页共 11 页
3. Function description
3.1. MCU
ADA789integrates ARM9 MCU with frequency up to 120MHz.
3.2. RAM, Flash
ADA789integrates 256Kbytes RAM, and 2Mbytes Flash.
3.3. Clock
ADA789should work with 26MHz crystal, with 10pF load capacitor, ±10 PPM accuracy.
Clock’s operating temperature：--20°C ~ 70°C，storage temperature
:
-40°C ~ 85°C.
3.4 Interface
3.4.1 UART
There are two UARTs in ADA789: user UART and debug UART. The max baud rate can be up
to 6Mpbs.
3.4.2 SPI
ADA789 supports high speed SPI with clock frequency up to 50MHz. Support master and slave
mode.
SDIO (in the same pins with SPI) supports master and slave mode with clock frequency up to
50MHz.
3.4.3 I
2
C
There are two I2C in ADA789, and the max frequency is 400kHz.
3.4.4 USB
Support full speed USB2.0 protocol. Support host and device.
3.4.5 ADC
Support 10-13 bit output.
3.4.6 GPIO
Support up to 14 GPIOs. Every GPIO supports interrupt, and can be wake up pin in sleep
mode.
3.4.7 CHIP_EN
CHIP_EN is system enable pin. When in high voltage, module is on. When in low voltage,
module is off. Please make sure CHIP_EN is high when power on.
3.5. Software programming
There are 6 test pins in the bottom, and they are connected with module pin10~15.
These 6 pins and GPIO_4, GPIO_14 are used for software programming.