Configuration Handbook - Kamami.pl

Altera Enhanced Configuration Devices1 The number of pages required in a system is not dependent onthe number of PLDs in the system, but depends on the numberof unique system configurations.External page mode input pins PGM[2..0]determine which page to useduring PLD configuration, and page pointers determine the datalocation. Each page pointer consists of a starting address register and alength count register. The word-addressable starting address register(23 bits) is used to determine where the page begins in the flash memory.The count register (25 bits) determines the length of the page counted innibbles (group of 4 bits equaling half of a byte). Figure 3–4 shows a blockdiagram of the option-bit space and its address locations.Figure 3–4. Option-Bit Memory Map0801Fh 24 CNT7 98 CNT7 0 22 ADDR7 1615 ADDR7 024 CNT1 98 CNT1 0 22 ADDR1 1615 ADDR1 024 CNT0 908009h 8 CNT0 0 22 ADDR0 1608008h 15 ADDR0 0For example, a page for the EPC16 configuration device must startbetween word addresses 0x08020h and 0xFFFFFh and cannot overlapwith other pages. See Figure 3–5 for an EPC16 page mode example usingthree pages.Altera Corporation 3–7April 2007 Configuration Handbook, Volume 2