LPC MicrocontrollersのトピックCould the LPC551x ISP via High-Speed crystal support @24Mhz?

Could the LPC551x ISP via High-Speed crystal support @24Mhz?

StephenYeh — Wed, 11 Jan 2023 09:15:38 GMT

Hi Sir,

I check the datasheet of LPC551x, the external crystal supports up to 25Mhz
, the customer wants to use the USB High-Speed ISP function, the spec. only 16MHz.
Could the LPC551x ISP via High-Speed crystal support @24Mhz(external crystal)?

Re: Could the LPC551x ISP via High-Speed crystal support @24Mhz?

ZhangJennie — Wed, 11 Jan 2023 13:31:06 GMT

Hi StephenYeh

Table 194 of UM11295 has a remark that states: “For USB HS ISP mode, 16 MHz crystal is required, and for the USB FS ISP mode, ROM uses FRO”. That's to say, we can't use 24M crystal for USB HS.

Have a nice day,

Jun Zhang