4.2. Memory map decode example

Figure 4‑2 shows a memory map decode example.

Figure 4.2. Memory map decode example

The combinational logic used to decode memory map addresses in Figure 4‑2 on page 4‑4 is shown in pseudo-HDL format in Table 4‑1.

Table 4.1. Memory map decode example pseudo-HDL

Logic expressionComment
MMDIN[0] = (MMDA[31:24] = 0x00) AND NOT(MMDnMREQ)SRAM
MMDIN[1] = (MMDA[31:24] = 0x04) AND NOT(MMDnMREQ)SRAM
MMDIN[2] = (MMDA[31:24] = 0x08) AND NOT(MMDnMREQ)Flash memory
MMDIN[4] = (MMDA[31:20] = 0x100) AND NOT(MMDnMREQ)Three unbuffered peripherals
MMDIN[5] = (MMDA[31:20] = 0x101) AND NOT(MMDnMREQ)
MMDIN[6] = (MMDA[31:20] = 0x102) AND NOT(MMDnMREQ)
MMDIN[7] = (MMDA[31:20] = 0x200) AND NOT(MMDnMREQ)Two buffered peripherals
MMDIN[8] = (MMDA[31:20] = 0x201) AND NOT(MMDnMREQ)
MMDIN[9] = (MMDA[31:28] = 0x4) AND NOT(MMDnMREQ)Off-chip SDRAM
MMDIN[10] = (MMDA[31:28] = 0x600) AND NOT(MMDnMREQ)Off-chip buffered peripherals
MMDIN[11] = (MMDA[31:28] = 0x601) AND NOT(MMDnMREQ)
MMDIN[12] = (MMDA[31:28] = 0x602) AND NOT(MMDnMREQ)
MMDIN[13] = (MMDA[31:28] = 0x603) AND NOT(MMDnMREQ)
MMDIN[14] = (MMDA[31:28] = 0x604) AND NOT(MMDnMREQ)
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