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전자부품 데이터시트 검색엔진 |
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전자부품 데이터시트 검색엔진 |
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DS42514 데이터시트(HTML) 15 Page - Advanced Micro Devices |
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DS42514 데이터시트(HTML) 15 Page - Advanced Micro Devices |
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DS42514 15 Autoselect Mode The autoselect mode provides manufacturer and de- vice identification, and sector protection verification, through identifier codes output on DQ7–DQ0. This mode is primarily intended for programming equip- ment to autom atic ally ma tch a dev ice to b e programmed with its corresponding programming al- gorithm. However, the autoselect codes can also be accessed in-system through the command register. To access the autoselect codes in-system, the host system can issue the autoselect command via the command register, as shown in Table 12. This method does not require V ID. Refer to the Autoselect Com- mand Sequence section for more information. Sector/Sector Block Protection and Unprotection (Note: For the following discussion, the term “sector” applies to both sectors and sector blocks. A sector block consists of two or more adjacent sectors that are protected or unprotected at the same time (see Table 7). Table 7. Bottom Boot Sector/Sector Block Addresses for Protection/Unprotection The hardware sector protection feature disables both program and erase operations in any sector. The hard- ware sector unprotection feature re-enables both program and erase operations in previously protected sectors. Sector protection and unprotection can be im- plemented as follows. Sector protection/unprotection requires V ID on the RE- SET# pin only, and can be implemented either in-system or via programming equipment. Figure 2 shows the algorithms and Figure 26 shows the timing diagram. This method uses standard microprocessor bus cycle timing. For sector unprotect, all unprotected sectors must first be protected prior to the first sector unprotect write cycle. Note that the sector unprotect algorithm unprotects all sectors in parallel. All previ- ous ly pr otected se ctor s must be i ndiv i dua lly re-protected. To change data in protected sectors effi- ciently, the temporary sector un protect function is available. See “Temporary Sector/Sector Block Unprotect”. The device is shipped with all sectors unprotected. It is possible to determine whether a sector is pro- tected or unprotected. See the Autoselect Mode section for details. Write Protect (WP#) The Write Protect function provides a hardware method of protecting certain boot sectors without using V ID. This function is one of two provided by the WP#/ACC pin. If the system asserts V IL on the WP#/ACC pin, the de- vice disables program and erase functions in the two “outermost” 8 Kbyte boot sectors independently of whether those sectors were protected or unprotected using the method described in “Sector/Sector Block Protection and Unprotection”. The two outermost 8 Kbyte boot sectors are the two sectors containing the lowest addresses in a bottom-boot-configured device, or the two sectors containing the highest addresses in a top-boot-configured device. If the system asserts V IH on the WP#/ACC pin, the de- vice reverts to whether the two outermost 8 Kbyte boot sectors were last set to be protected or unprotected. That is, sector protection or unprotection for these two sectors depends on whether they were last protected or unprotected using the method described in “Sec- tor/Sector Block Protection and Unprotection”. Note that the WP#/ACC pin must not be left floating or unconnected; inconsistent behavior of the device may result. Temporary Sector/Sector Block Unprotect (Note: For the following discussion, the term “sector” applies to both sectors and sector blocks. A sector block consists of two or more adjacent sectors that are protected or unprotected at the same time (see Table 7). This feature allows temporary unprotection of previ- ously protected sectors to change data in-system. The Sector Unprotect mode is activated by setting the RE- Sector / Sector Block A19–A12 Sector / Sector Block Size SA38 11111XXX 64 Kbytes SA37 –SA35 11110XXX, 11101XXX, 11100XXX 192 (3x64) Kbytes SA34 –SA31 110XXXXX 256 (4x64) Kbytes SA30 –SA27 101XXXXX 256 (4x64) Kbytes SA26 –SA23 100XXXXX 256 (4x64) Kbytes SA22 –SA19 011XXXXX 256 (4x64) Kbytes SA18 –SA15 010XXXXX 256 (4x64) Kbytes SA14 –SA11 001XXXXX 256 (4x64) Kbytes SA10 –SA8 00001XXX, 00010XXX, 00011XXX 192 (3x64) Kbytes SA7 00000111 8 Kbytes SA6 00000110 8 Kbytes SA5 00000101 8 Kbytes SA4 00000100 8 Kbytes SA3 00000011 8 Kbytes SA2 00000010 8 Kbytes SA1 00000001 8 Kbytes SA0 00000000 8 Kbytes |
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