M7020R datasheet(128/150 Pages) STMICROELECTRONICS

128 / 150 page

M7020R

128/150

SRAM READ with a Table of Up to Eight Devices

The following explains the SRAM READ operation

completed through a table of up to eight devices

using the following parameters: TLSZ = 01. Figure

94, page 129 diagrams a block of eight devices.

The following assumes that SRAM access is suc-

cessfully achieved through M7020R Device 0. Fig-

ure 95, page 130 and Figure 96, page 131 show

timing diagrams for Device 0 and Device 7, re-

spectively.

– Cycle 1A: The host ASIC applies the READ In-

struction on the CMD[1:0] using CMDV = 1. The

DQ Bus supplies the address, with DQ[20:19]

set to '10' to select the SRAM address. The host

ASIC selects the device for which ID[4:0] match-

es the DQ[25:21] lines. During this cycle the

host ASIC also supplies SADR[21:20] on

CMD[8:7].

– Cycle 1B: The host ASIC continues to apply the

READ Instruction on the CMD[1:0] using

CMDV = 1. The DQ Bus supplies the address

with DQ[20:19] set to '10' to select the SRAM

address.

– Cycle 2: The host ASIC floats DQ[67:0] to a 3-

state condition.

– Cycle 3: The host ASIC keeps DQ[67:0] in a 3-

state condition.

– Cycle 4: The selected device starts to drive

DQ[67:0].

– Cycle 5: The selected device continues to drive

DQ[67:0] and drives ACK from high-Z to low

– Cycle 6: The selected device drives the READ

address on SADR[21:0]. It also drives ACK

high, CE_L low, WE_L high, and ALE_L low.

– Cycle 7: The selected device drives CE_L,

ALE_L, WE_L, and the DQ Bus in a 3-state con-

dition. It continues to drive ACK low.

At the end of Cycle 7, the selected device floats

ACK in 3-state condition and a new command can

begin.

M7020R датащи(PDF) 128 Page - STMicroelectronics

M7020R датащи(HTML) 128 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

датащи скачать

ссылки URL