rickman wrote:> Eric Smith wrote: >> "rickman" <gnuarm@gmail.com> writes: >>> Unless there is some clear advantage >>> to using a part like the AT91M40800, I would expect one of the SAM7S >>> parts running at 1.8 volts for both core and I/O to be a much better >>> choice. >> >> The datasheet indicates that the AT91SAM7S parts require 3.0-3.6V >> for the flash memory. Even just to read it. Otherwise it would be >> OK. > > Yes, you are right. They also have a separate VDDIN pin to power the > LDO. Seems rather silly that they only offer 1.8 and 3.3 volt IO > standards given that you have to have 3.3 volts for the part to work > from Flash. I guess there is some market for 1.8 volt IOs though.If the choice had bveen made to support the lower voltage flash, then this would have affected the maximum clock frequency of the device. You can't run the SAM7S from a Lithium cell unless you have a voltage regulator stepping up to minimum 3.0V. The AT91M40800 will work at 1.8V with external 1.8V flash. -- Best Regards, Ulf Samuelsson ulf@a-t-m-e-l.com This message is intended to be my own personal view and it may or may not be shared by my employer Atmel Nordic AB
ARM microcontroller with 2.0-3.2V supply range
Started by ●November 4, 2006
Reply by ●November 8, 20062006-11-08
Reply by ●November 8, 20062006-11-08
Ulf Samuelsson wrote:> If the choice had bveen made to support the lower voltage flash, > then this would have affected the maximum clock frequency of the device. > You can't run the SAM7S from a Lithium cell unless you have > a voltage regulator stepping up to minimum 3.0V. > The AT91M40800 will work at 1.8V with external 1.8V flash. >could be the future SAM7L will satisfy his needs