Motor de Búsqueda de Datasheet de Componentes Electrónicos |
|
TSC87C52-16CJR Datasheet(PDF) 11 Page - TEMIC Semiconductors |
|
TSC87C52-16CJR Datasheet(HTML) 11 Page - TEMIC Semiconductors |
11 / 24 page TSC87C52 11 MATRA MHS Rev. C – 10 Sept 1997 Preliminary EPROM EPROM Structure The TSC87C52 EPROM is divided in two different arrays: D the code array: 8 Kbytes. D the encryption array: 64 bytes. In addition a third non programmable array is implemented: D the signature array: 4 bytes. EPROM Lock System The program Lock system, when programmed, protects the on–chip program against software piracy. Encryption Array Within the EPROM array are 64 bytes of encryption array that are initially unprogrammed (all 1’s). Every time a byte is addressed during program verify, 6 address lines are used to select a byte of the encryption array. This byte is then exclusive–NOR’ed (XNOR) with the code byte, creating an encryption verify byte. The algorithm, with the encryption array in the unprogrammed state, will return the code in its original, unmodified form. When using the encryption array, one important factor needs to be considered. If a byte has the value FFh, verifying the byte will produce the encryption byte value. If a large block (>64 bytes) of code left unprogrammed, a verification routine will display the content of the encryption array. For this reason all the unused code bytes should be programmed with random values. This will ensure program protection. EPROM Programming Set–up modes In order to program and verify the EPROM or to read the signature bytes, the TSC87C52 is placed in specific set–up modes (see Figure 8). Control and program signals must be held at the levels indicated in Table 6. Definition of terms Address Lines: P1.0–P1.7, P2.0–P2.4 respectively for A0–A12 Data Lines: P0.0–P0.7 for D0–D7 Control Signals: RST, PSEN, P2.6, P2.7, P3.3, P3.6, P3.7. Program Signals: ALE/PROG, EA/VPP. Table 6 EPROM Set–up Modes Mode RST PSEN ALE/ PROG EA/VPP P2.6 P2.7 P3.3 P3.6 P3.7 Program Code data 1 0 12.75V 0 1 1 1 1 Verify Code data 1 0 1 1 0 0 1 1 Program Encryption Array Address 0–3Fh 1 0 12.75V 0 1 1 0 1 Read Signature Bytes 1 0 1 1 0 0 0 0 |
Número de pieza similar - TSC87C52-16CJR |
|
Descripción similar - TSC87C52-16CJR |
|
|
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 |