UPSD3422 datasheet(193/293 Pages) STMICROELECTRONICS

193 / 293 page

uPSD34xx

PSD module

193/293

Table 103.

HDL statement example generated from PSDsoft express for memory

map

Figure 65.

PSDsoft express memory mapping

28.2.4

EEPROM emulation

EEPROM emulation is needed if it is desired to repeatedly change only a small number of

bytes of data in Flash memory. In this case EEPROM emulation is needed because

although Flash memory can be written byte-by-byte, it must be erased sector-by-sector, it is

not erasable byte-by-byte (unlike EEPROM which is written AND erased byte-by-byte). So

changing one or two bytes in Flash memory typically requires erasing an entire sector each

time only one byte is changed within that sector.

However, two of the 8K byte sectors of Secondary Flash memory may be used to emulate

EEPROM by using a linked-list software technique to create a small data set that is

rs0

((address

≥ ^h0000) & (address ≤ ^h1FFF));

csiop

((address

≥ ^h2000) & (address ≤ ^h20FF));

fs0

((address

≥ ^h0000) & (address ≤ ^h3FFF));

fs1

((address

≥ ^h4000) & (address ≤ ^h7FFF));

fs2

((page == 0)

& (address

≥ ^h8000)

(address

≤ ^hBFFF));

fs3

((page == 0)

& (address

≥ ^hC000)

(address

≤ ^hFFFF));

fs4

((page == 1)

& (address

≥ ^h8000)

(address

≤ ^hBFFF));

fs5

((page == 1)

& (address

≥ ^hC000)

(address

≤ ^hFFFF));

fs6

((page == 2)

& (address

≥ ^h8000)

(address

≤ ^hBFFF));

fs7

((page == 2)

& (address

≥ ^hC000)

(address

≤ ^hFFFF));

csboot0 =

((address

≥ ^h8000) & (address ≤ ^h9FFF));

csboot1 =

((address

≥ ^hA000) & (address ≤ ^hBFFF));

csboot2 =

((address

≥ ^hC000) & (address ≤ ^hDFFF));

csboot3 =

((address

≥ ^hE000) & (address ≤ ^hFFFF));

UPSD3422 Datasheet(PDF) 193 Page - STMicroelectronics

UPSD3422 Datasheet(HTML) 193 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL