Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
CAT34C02HU4I-GT4A Datasheet(PDF) 8 Page - ON Semiconductor |
|
CAT34C02HU4I-GT4A Datasheet(HTML) 8 Page - ON Semiconductor |
8 / 15 page CAT34C02 http://onsemi.com 8 Software Write Protection The lower half of memory (first 128 bytes) can be protected against Write requests by setting one of two Software Write Protection (SWP) flags. The Permanent Software Write Protection (PSWP) flag can be set or read while all address pins are at regular CMOS levels (GND or VCC), whereas the very high voltage VHV must be present on address pin A0 to set, clear or read the Reversible Software Write Protection (RSWP) flag. The D.C. OPERATING CONDITIONS for RSWP operations are shown in Table 8. The SWP commands are listed in Table 9. All commands are preceded by a START and terminated with a STOP, following the ACK or NoACK from the CAT34C02. All SWP related Slave addresses use the pre−amble: 0110 (6h), instead of the regular 1010 (Ah) used for memory access. For PSWP commands, the three address pins can be at any logic level, whereas for RSWP commands the address pins must be at pre−assigned logic levels. VHV is interpreted as logic ‘1’. The VHV condition must be established on pin A0 before the START and maintained just beyond the STOP. Otherwise an RSWP request could be interpreted by the CAT34C02 as a PSWP request. The SWP Slave addresses follow the standard I2C convention, i.e. to read the state of the SWP flag, the LSB of the Slave address must be ‘1’, and to set or clear a flag, it must be ‘0’. For Write commands a dummy byte address and dummy data byte must be provided (Figure 14). In contrast to a regular memory Read, a SWP Read does not return Data. Instead the CAT34C02 will respond with NoACK if the flag is set and with ACK if the flag is not set. Therefore, the Master can immediately follow up with a STOP, as there is no meaningful data following the ACK interval (Figure 15). Hardware Write Protection With the WP pin held HIGH, the entire memory, as well as the SWP flags are protected against Write operations, see Memory Protection Map below. If the WP pin is left floating or is grounded, it has no impact on the operation of the CAT34C02. The state of the WP pin is strobed on the last falling edge of SCL immediately preceding the first data byte (Figure 9). If the WP pin is HIGH during the strobe interval, the CAT34C02 will not acknowledge the data byte and the Write request will be rejected. Software Write Protectable (by setting the write protect flags) FFH 00H 7FH Hardware Write Protectable (by connecting WP pin to VCC) Figure 13. Memory Protection Map Table 8. RSWP D.C. OPERATING CONDITIONS (Note 11) Symbol Parameter Test Conditions Min Max Units DVHV A0 Overdrive (VHV − VCC) 1.7 V < VCC < 3.6 V 4.8 V IHVD A0 High Voltage Detector Current 0.1 mA VHV A0 Very High Voltage 7 10 V IHV A0 Input Current @ VHV 1 mA 11. To prevent damaging the CAT34C02 while applying VHV, it is strongly recommended to limit the power delivered to pin A0, by inserting a series resistor (> 1.5 kW) between the supply and the input pin. The resistance is only limited by the combination of VHV and maximum IHVD. While the resistor can be omitted if VHV is clamped well below 10 V, it nevertheless provides simple protection against EOS events. As an example: VCC = 1.7 V, VHV = 8 V, 1.5 kW < RS < 15 kW. |
Número de pieza similar - CAT34C02HU4I-GT4A |
|
Descripción similar - CAT34C02HU4I-GT4A |
|
|
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 |