33
C005383_10 CR80XX Integration Guide
Notes: 1.
T
grpw
is programmable using command register 0x1EA.
2.
T
TimeouT
is programmable using command register 0x9F.
11.2 – Communications from Sleep Mode
(continued)
11.3 – Timing Specifications
Rapid Scanning and Returning to Sleep
The following diagram shows the timing diagram
for scanning a barcode when the unit is in sleep
mode. When register
0x9F
is minimized, the unit
will consume the minimum amount of power
possible. Please refer to Section 12.3 for all
appropriate timing values.
1. Host asserts
nWakeUp
2. After
T
wu
, CR8000 negates
PwrDwn
3. After
T
cmddelay
, host can assert
nTrigger
4. Output signals are invalid during
setup time
T
su
5. CR8000 decodes barcode and
asserts
nGoodRead
6. CR8000 transmits data to host
7. After CR8000 transmits data, engine goes to
sleep after
T
TimeouT
period programmed in
register
0x9F
Signal
Description
Min
Typical
Max
Unit
T
wupw
nWakeUp
pulse width
10
20
msec
T
wu
Time between
nWakeUp
asserted and
CR8000 ready
120
msec
T
su
Time between
nWakeUp
asserted and
outputs valid
5
5
10
msec
T
cmddelay
Time between CR8000 ready and when
nTrigger
can be asserted
0
1
msec
T
decode
Time between
nTrigger
asserted and
nGoodRead
asserted (decode time)
100
msec
T
grpw
nGoodRead
pulse width
See Note 1
T
TimeouT
Time between data transfer and sleep state
See Note 2
msec
T
WUPW
nWakeUp
T
WU
T
CMDDELAY
PwrDwn
T
DECODE
nTrigger
T
SU
T
GRPW
nGoodRead
T
TIMEOUT
DATA
Data
Wake-Up Barcode Read Timing Diagram
