M58LR128HT datasheet(39/112 Pages) STMICROELECTRONICS

39 / 112 page

M58LR128HT, M58LR128HB

Configuration Register

39/112

6.3

Wait Polarity bit (CR10)

The Wait Polarity bit is used to set the polarity of the Wait signal used in Synchronous Burst

Read mode. During Synchronous Burst Read mode the Wait signal indicates whether the

data output are valid or a WAIT state must be inserted.

When the Wait Polarity bit is set to ‘0’ the Wait signal is active Low. When the Wait Polarity

bit is set to ‘1’ the Wait signal is active High.

6.4

Data Output Configuration bit (CR9)

The Data Output Configuration bit is used to configure the output to remain valid for either

one or two clock cycles during synchronous mode.

When the Data Output Configuration Bit is ’0’ the output data is valid for one clock cycle,

when the Data Output Configuration Bit is ’1’ the output data is valid for two clock cycles.

The Data Output Configuration must be configured using the following condition:

●

tK > tKQV + tQVK_CPU

where

●

tK is the clock period

●

tQVK_CPU is the data setup time required by the system CPU

●

tKQV is the clock to data valid time.

If this condition is not satisfied, the Data Output Configuration bit should be set to ‘1’ (two

clock cycles). Refer to Figure 5: X-Latency and data output configuration example.

6.5

Wait Configuration bit (CR8)

The Wait Configuration bit is used to control the timing of the Wait output pin, WAIT, in

Synchronous Burst Read mode.

When WAIT is asserted, Data is Not Valid and when WAIT is de-asserted, Data is Valid.

When the Wait Configuration bit is Low (set to ’0’) the Wait output pin is asserted during the

WAIT state. When the Wait Configuration bit is High (set to ’1’), the Wait output pin is

asserted one data cycle before the WAIT state.

6.6

Burst Type bit (CR7)

The Burst Type bit determines the sequence of addresses read during Synchronous Burst

Reads.

The Burst Type bit is High (set to ’1’), as the memory outputs from sequential addresses

only.

See Table 12: Burst type definition, for the sequence of addresses output from a given

starting address in sequential mode.

M58LR128HT 数据表(PDF) 39 Page - STMicroelectronics

M58LR128HT 数据表(HTML) 39 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

数据表下载