-----Original Message----- From: Lauri Pirttiaho To: PICLIST@MITVMA.MIT.EDU Date: Wednesday, June 17, 1998 12:12 PM Subject: Re: Differences between 16C84 & 16F84 (was RE: 16F84) >>At 09:50 15/06/98 +0200, Jim robertson wrote: >>Ha! What a joke. They told you the difference was EEPROM Versus FLASH! >>There is no difference BECAUSE THE 16F8X ARE NOT "TRUE" FLASH DEVICES!!! >>Microchip are being misleading (They are not the only chip manufacturer >>calling EEPROM "FLASH" though. Atmel, I believe also do it) > >On the contrary! It looks very much like the 16F8X are true FLASH devices >while 16C84 was a true EEPROM device. Now, I do not know on what premises >or information Jim is saying 16F8X is not true FLASH. You are not right, Jim - yes! > >It may be helpful to make it clear what is the difference between an EEPROM >and a FLASH. The difference is not only that between a byte erase and a >block erase even though this is a consequence of the design. You may have >an EEPROM with only a block erase. The most important difference is the >memory cell design: in EEPROM you have a two transistor cell, in FLASH >there is only one (FAMOS) transistor in one bit memory cell. Therefore >the silicon area of the program memory in a FLASH device is smaller and >that is one possible source of the extra chip area the designers had and >thus were able to double the size of the register file. > >I know that 16F84 has to be erased prior to reprogramming which is indicative >that the memory cell is not rewritable. I would like to hear what happens >with a 16C84 part? Do you have to erase it or does it erase byte by byte >while being programmed like an EEPROM does? As C84 as F84 - it is possible to program any program memory location without erasing the all chip. ================================== Alex Torres, Kharkov, Ukraine (exUSSR) E-Mail: altor@geocities.com 2:461/28 FidoNet Home Page: http://www.geocities.com/SiliconValley/Lab/6311