Symbol SE 923, Руководство по интеграции

Страница: 45 / 238

4-1
Chapter 4
Application Notes
AC Electrical Characteristics
For the AC electrical characteristics shown in Table 4-1 , Tamb = -20
°
C to 50
°
C,
V
BATT
= 3.3 V to 5.5 V. All output lines are measured with 10K pull-up.
Table 4-1. Timing Characteristics
Symbol Figure Parameter Min Max Unit
General Characteristics
t
f
Figure 4-1 High-to-Low fall time, all outputs,
C
L
= 50 pf
1.0 µsec
t
r
Figure 4-1 Low-to-High rise time, all outputs,
C
L
= 50 pf
1.0 µsec
Serial I/O Timing, Host Transmit
t
rlcl
Figure 4-2 Request to Send low to Clear to Send low 0 25 msec
t
clxl
Figure 4-2 Clear to Send low to first start bit note 2
Notes:
1. If byte to byte delay exceeds the maximum specified time, a transmission error is declared. The sender is
expected to retransmit the packet in its entirety.
2. The host may hold the Host RTS* low indefinitely, but it will lock out the SE-923 from transmitting.
3. The decoder may transmit any time the Host RTS* is high.
4. The host should release its Host RTS* as soon as possible after transmitting so that the decoder can process the
message.
5. The SE-923's micro-controller is in full operation whenever the PWRDWN line is driven low.
6. See the
Power Management on page 1-5 if trigger is not pulled after the maximum specified amount of time.
7. In addition, refer to Parameter # 0x88 on page 5-10 and Parameter # 0x8A on page 5-13.