![]() |
Electronic Components Datasheet Search |
|
87C749 Datasheet(PDF) 16 Page - NXP Semiconductors |
|
|
87C749 Datasheet(HTML) 16 Page - NXP Semiconductors |
16 / 22 page ![]() Philips Semiconductors Preliminary specification 83C749/87C749 80C51 8-bit microcontroller family 2K/64 OTP/ROM, 5 channel 8-bit A/D, PWM, low pin count 1998 Apr 23 16 Programming and Verifying Security Bits Security bits are programmed employing the same techniques used to program the USER EPROM and KEY arrays using serial data streams and logic levels on port pins indicated in Table 3. When programming either security bit, it is not necessary to provide address or data information to the 87C749 on ports 1 and 3. Verification occurs in a similar manner using the RESET serial stream shown in Table 3. Port 3 is not required to be driven and the results of the verify operation will appear on ports 1.6 and 1.7. Ports 1.7 contains the security bit 1 data and is a logical one if programmed and a logical zero if not programmed. Likewise, P1.6 contains the security bit 2 data and is a logical one if programmed and a logical zero if not programmed. Table 3. Implementing Program/Verify Modes OPERATION SERIAL CODE P0.1 (PGM/) P0.2 (VPP) Program user EPROM 296H –* VPP Verify user EPROM 296H VIH VIH Program key EPROM 292H –* VPP Verify key EPROM 292H VIH VIH Program security bit 1 29AH –* VPP Program security bit 2 298H –* VPP Verify security bits 29AH VIH VIH NOTE: * Pulsed from VIH to VIL and returned to VIH. EPROM PROGRAMMING AND VERIFICATION Tamb = 21°C to +27°C, VCC = 5V ±10%, VSS = 0V SYMBOL PARAMETER MIN MAX UNIT 1/tCLCL Oscillator/clock frequency 1.2 6 MHz tAVGL1 Address setup to P0.1 (PROG–) low 10 µs + 24tCLCL tGHAX Address hold after P0.1 (PROG–) high 48tCLCL tDVGL Data setup to P0.1 (PROG–) low 38tCLCL tDVGL Data setup to P0.1 (PROG–) low 38tCLCL tGHDX Data hold after P0.1 (PROG–) high 36tCLCL tSHGL VPP setup to P0.1 (PROG–) low 10 µs tGHSL VPP hold after P0.1 (PROG–) 10 µs tGLGH P0.1 (PROG–) width 90 110 µs tAVQV2 VPP low (VCC) to data valid 48tCLCL tGHGL P0.1 (PROG–) high to P0.1 (PROG–) low 10 µs tSYNL P0.0 (sync pulse) low 4tCLCL tSYNH P0.0 (sync pulse) high 8tCLCL tMASEL ASEL high time 13tCLCL tMAHLD Address hold time 2tCLCL tHASET Address setup to ASEL 13tCLCL tADSTA Low address to address stable 13tCLCL NOTES: 1. Address should be valid at least 24tCLCL before the rising edge of P0.2 (VPP). 2. For a pure verify mode, i.e., no program mode in between, tAVQV is 14tCLCL maximum. |
Similar Part No. - 87C749 |
|
Similar Description - 87C749 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List 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 |