S75WS256NDFBAWMB datasheet(166/216 Pages) SPANSION

166 / 216 page

164

S75WS256Nxx Based MCPs

S75WS-N-00_A0 February 17, 2005

Ad van c e

Inf o rmation

31.2.7

Operating Mode (BCR[15]): Default = Asynchronous Operation

The operating mode bit selects either synchronous burst operation or the default asynchronous

mode of operation.

31.3

Refresh Configuration Register

The refresh configuration register (RCR) defines how the CellularRAM device performs its trans-

parent self refresh. Altering the refresh parameters can dramatically reduce current consumption

during standby mode. Page mode control is also embedded into the RCR. Table 31.5 below de-

scribes the control bits used in the RCR. At power-up, the RCR is set to 0070h. The RCR is

accessed using CRE and A[19] Low.

31.3.1

Partial Array Refresh (RCR[2:0]): Default = Full Array Refresh

The PAR bits restrict refresh operation to a portion of the total memory array. This feature allows

the device to reduce standby current by refreshing only that part of the memory array required

by the host system. The refresh options are full array, one-half array, one-quarter array, three-

quarters array, or none of the array. The mapping of these partitions can start at either the be-

ginning or the end of the address map (see Table 31.6 through Table 31.8).

Table 31.5 Refresh Configuration Register Mapping

Table 31.6 128Mb Address Patterns for PAR (RCR[4] = 1)

RCR[2]

RCR[1]

RCR[0]

Active Section

Address Space

Size

Density

Full die

000000h–7FFFFFh

8 Meg x 16

128Mb

One-half of die

000000h–3FFFFFh

4 Meg x 16

64Mb

One-quarter of die

000000h–1FFFFFh

2 Meg x 16

32Mb

One-eighth of die

000000h–0FFFFFh

1 Meg x 16

16Mb

None of die

0 Meg x 16

0Mb

One-half of die

400000h–7FFFFFh

4 Meg x 16

64Mb

PAR

Read Configuration

Address Bus

All must be set to "0"

Deep Power-Down

DPD Enable

DPD Disable (default)

RCR[4]

A[18:8]

Select

Reserved

TCR

A[22:20]

A19

Select RCR

Select BCR

RCR[19]

All must be set to "0"

RCR[1] RCR[0]

Refresh Coverage

RCR[2]

Full array (default)

Bottom 1/2 array

Bottom 1/4 array

Bottom 1/8 array

Top 1/2 array

Top 1/4 array

DPD

Must be set to "0"

Page

Page Mode Enable/Disable

Page Mode Disabled (default)

Page Mode Enable

RCR[7]

18–8

22–20

None of array

Top 3/4 array

RCR[6]

RCR[5]

Maximum Case Temp

+85ºC (default)

+70ºC

+45ºC

+15ºC

S75WS256NDFBAWMB bảng dữ liệu(PDF) 166 Page - SPANSION

S75WS256NDFBAWMB bảng dữ liệu(HTML) 166 Page - SPANSION

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

bảng dữ liệu tải về

Link URL