The The The input is The The The input is The The The input is The The or newer avr-libc<\/p>\n The Sources: pgm_read_byte() Abstract The pgm_read_byte() is a macro that reads a byte of data stored in a specified address(PROGMEM area). Source Code The pgm_read_byte() is defined in hardware\/tools\/avr\/avr\/include\/avr\/pgmspace.h as below. #define pgm_read_byte(address_short) pgm_read_byte_near(address_short) The input is address_short and calls the pgm_read_byte_near() macro. pgm_read_byte_near() Abstract The pgm_read_byte_near() is a macro that reads a byte of data stored […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[19],"tags":[],"class_list":["post-652","post","type-post","status-publish","format-standard","hentry","category-avr"],"_links":{"self":[{"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/posts\/652","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=652"}],"version-history":[{"count":13,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/posts\/652\/revisions"}],"predecessor-version":[{"id":673,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=\/wp\/v2\/posts\/652\/revisions\/673"}],"wp:attachment":[{"href":"https:\/\/blog.bachi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=652"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=652"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.bachi.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=652"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}pgm_read_byte()<\/code> is a macro that reads a byte of data stored in a specified address(PROGMEM area).<\/p>\nSource Code<\/h4>\n
pgm_read_byte()<\/code> is defined in hardware\/tools\/avr\/avr\/include\/avr\/pgmspace.h<\/code> as below.<\/p>\n\r\n#define pgm_read_byte(address_short) pgm_read_byte_near(address_short)\r\n<\/pre>\n
address_short<\/code> and calls the pgm_read_byte_near()<\/code> macro.<\/p>\npgm_read_byte_near()<\/h3>\n
Abstract<\/h4>\n
pgm_read_byte_near()<\/code> is a macro that reads a byte of data stored in a specified address(PROGMEM area).<\/p>\nSource Code<\/h4>\n
pgm_read_byte_near()<\/code> is defined in hardware\/tools\/avr\/avr\/include\/avr\/pgmspace.h<\/code> as below.<\/p>\n\r\n#define pgm_read_byte_near(address_short) __LPM((uint16_t)(address_short))\r\n<\/pre>\n
address_short<\/code> and the macro converts the address_short<\/code> to uint16_t<\/code>, then calls __LPM()<\/code> macro.<\/p>\n__LPM()<\/h3>\n
Abstract<\/h4>\n
__LPM()<\/code> is a macro that reads a byte of data stored in a specified address(PROGMEM area).<\/p>\nSource Code<\/h4>\n
__LPM()<\/code> is defined in hardware\/tools\/avr\/avr\/include\/avr\/pgmspace.h<\/code> as below.<\/p>\n\r\n#define __LPM(addr) __LPM_enhanced__(addr)\r\n<\/pre>\n
addr<\/code> and just calls __LPM_enhanced__()<\/code>.
\nSee Intrinsic Functions<\/a><\/p>\n__LPM_enhanced__()<\/h3>\n
Abstract<\/h4>\n
__LPM_enhanced()<\/code> is an assembler code that reads a byte of data stored in a specified address(PROGMEM area).<\/p>\nSource Code<\/h4>\n
__LPM_enhanced()<\/code> is defined in hardware\/tools\/avr\/avr\/include\/avr\/pgmspace.h<\/code> as below.<\/p>\n\r\n#define __LPM_enhanced__(addr) \\\r\n(__extension__({ \\\r\n uint16_t __addr16 = (uint16_t)(addr); \\\r\n uint8_t __result; \\\r\n __asm__ \\\r\n ( \\\r\n "lpm %0, Z" "\\n\\t" \\\r\n : "=r" (__result) \\\r\n : "z" (__addr16) \\\r\n ); \\\r\n __result; \\\r\n}))\r\n<\/pre>\n\r\n#define __LPM_classic__(addr) \\\r\n(__extension__({ \\\r\n uint16_t __addr16 = (uint16_t)(addr); \\\r\n uint8_t __result; \\\r\n __asm__ \\\r\n ( \\\r\n "lpm" "\\n\\t" \\\r\n "mov %0, r0" "\\n\\t" \\\r\n : "=r" (__result) \\\r\n : "z" (__addr16) \\\r\n : "r0" \\\r\n ); \\\r\n __result; \\\r\n}))\r\n<\/pre>\nlpm<\/code>, short for Load Program Memory, is a instruction that reads a byte of data from PROGMEM area. It substitue a data at addr<\/code> for __result<\/code>, then returns the __result<\/code>.<\/p>\n
\npgm_read_byte() marco<\/a>
\npgm_read_byte_near() marco<\/a>
\n__LPM() marco<\/a>
\n__LPM_enhanced__() marco<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"