Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
M27W512-200B6F Datasheet(PDF) 7 Page - STMicroelectronics |
|
M27W512-200B6F Datasheet(HTML) 7 Page - STMicroelectronics |
7 / 21 page 7/21 M27W512 pacitors. It is recommended that a 0.1µF ceramic capacitor be used on every device between VCC and VSS. This should be a high frequency capaci- tor of low inherent inductance and should be placed as close to the device as possible. In addi- tion, a 4.7µF bulk electrolytic capacitor should be used between VCC and VSS for every eight devic- es. The bulk capacitor should be located near the power supply connection point.The purpose of the bulk capacitor is to overcome the voltage drop caused by the inductive effects of PCB traces. Figure 6. Programming Flowchart Programming The M27W512 has been designed to be fully com- patible with the M27C512 and has the same elec- tronic signature. As a result the M27W512 can be programmed as the M27C512 on the same pro- gramming equipment applying 12.75V on VPP and 6.25V on VCC. The M27W512 can use PRESTO IIB Programming Algorithm that drastically reduc- es the programming time. Nevertheless to achieve compatibility with all programming equipments, PRESTO II Programming Algorithm can be used as well. When delivered (and after each ‘1’s era- sure for UV EPROM), all bits of the M27W512 are in the '1' state. Data is introduced by selectively programming '0's into the desired bit locations. Al- though only '0's will be programmed, both '1's and '0's can be present in the data word. The only way to change a ‘0’ to a ‘1’s by die exposure to ultravi- olet light (UV EPROM). The M27W512 is in the programming mode when VPP input is at 12.75V and E is pulsed to VIL. The data to be programmed is applied to 8 bits in parallel to the data output pins. The levels required for the address and data inputs are TTL. VCC is specified to be 6.25V ± 0.25V. PRESTO IIB Programming Algorithm PRESTO IIB Programming Algorithm allows the whole array to be programmed with a guaranteed margin, in a typical time of 6.5 seconds. This can be achieved with STMicroelectronics M27W512 due to several design innovations described in the M27W512 datasheet to improve programming ef- ficiency and to provide adequate margin for reli- ability. Before starting the programming the internal MARGIN MODE circuit must be set in or- der to guarantee that each cell is programmed with enough margin. Then a sequence of 100µs pro- gram pulses is applied to each byte until a correct verify occurs (see Figure 6.). No overprogram pulses are applied since the verify in MARGIN MODE at VCC much higher than 3.6V, provides the necessary margin. Program Inhibit Programming of multiple M27W512s in parallel with different data is also easily accomplished. Ex- cept for E, all like inputs including GVPP of the par- allel M27W512 may be common. A TTL low level pulse applied to a M27W512's E input, with VPP at 12.75V, will program that M27W512. A high level E input inhibits the other M27W512s from being programmed. Program Verify A verify (read) should be performed on the pro- grammed bits to determine that they were correct- ly programmed. The verify is accomplished with G at VIL. Data should be verified with tELQV after the falling edge of E. Electronic Signature The Electronic Signature (ES) mode allows the reading out of a binary code from an EPROM that will identify its manufacturer and type. This mode is intended for use by programming equipment to automatically match the device to be programmed with its corresponding programming algorithm. The ES mode is functional in the 25°C ± 5°C am- bient temperature range that is required when pro- gramming the M27W512. To activate the ES mode, the programming equipment must force 11.5V to 12.5V on address line A9 of the M27W512. Two identifier bytes may then be se- AI00738C n = 0 Last Addr VERIFY E = 100 µs Pulse ++n = 25 ++ Addr VCC = 6.25V, VPP = 12.75V FAIL CHECK ALL BYTES 1st: VCC = 5V 2nd: VCC = 2.7V YES NO YES NO YES NO SET MARGIN MODE RESET MARGIN MODE |
Número de pieza similar - M27W512-200B6F |
|
Descripción similar - M27W512-200B6F |
|
|
Enlace URL |
Política de Privacidad |
ALLDATASHEET.ES |
¿ALLDATASHEET es útil para Ud.? [ DONATE ] |
Todo acerca de Alldatasheet | Publicidad | Contáctenos | Política de Privacidad | Intercambio de Enlaces | Lista de Fabricantes All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |