我有个产品想用PCA9698DGG这个芯片扩展IO,只做输出使用,我想请问:
1、由于我MCU引脚有限,只有三根引脚用于扩展,我想接SDA、SCL和RESET,因为只做输出使用,请问OE输出使能引脚可以直接接低电平吗?
2、因为只做输出使用,INT引脚可以不接吗?
3、我扩展IO的目的是模拟多路SPI接口,请问这个芯片的响应速度是否可以满足?(我使用的SPI速度不是很高)
非常感谢!
Hi
For your questions please see comment:
1:Please read datasheet describe about OE function:
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• When a LOW level is applied to the OE pin, with OEPOL = 0 (register 2Ah, bit 4) or a
HIGH level is applied to the OE pin, with OEPOL = 1 (register 2Ah, bit 0), all the I/Os
configured as outputs are enabled and the logic value programmed in their respective
OP registers is applied to the pins.
• When a HIGH level is applied to the OE pin, with OEPOL = 0 (register 2Ah, bit 0) or a
LOW level is applied to the OE pin, with OEPOL = 1 (register 2Ah, bit 0), all the I/Os
configured as outputs are 3-stated.
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2:Yes
3:what's your SPI speed?
Thanks!