Datasheet

DS1921H/Z
27 of 45
ROM FUNCTIONS FLOW CHART Figure 13-1
To Memory Functions
Flow Chart (Figure 10)
DS1921 TX Bit 63
Master TX Bit 63
DS1921 TX Bit 63
DS1921 TX Bit 1
Master TX Bit 1
DS1921 TX Bit 1
DS1921 TX Bit 0
Master TX Bit 0
DS1921 TX Bit 0
Bit 63 Match?
Bit 1 Match?
Bit 0 Match?
F0H
Search
ROM?
N
Y
N
Y
Y
N
Y
N
DS1921 TX Bit 63
Master TX Bit 63
DS1921 TX Bit 63
DS1921 TX Bit 1
Master TX Bit 1
DS1921 TX Bit 1
DS1921 TX Bit 0
Master TX Bit 0
DS1921 TX Bit 0
Bit 63 Match?
Bit 1 Match?
Bit 0 Match?
Cond. Met?
ECH
Cond. Search
ROM?
N
Y
N
Y
N
Y
Y
N
Y
N
Master TX Bit 63
Master TX Bit 1
Master TX Bit 0
Bit 63 Match?
Bit 1 Match?
Bit 0 Match?
55H
Match
ROM?
N
Y
N
Y
Y
N
Y
N
DS1921 TX
CRC Byte
DS1921 TX
Temp. Range
Code and
Serial Number
6 Bytes
DS1921 TX
Family Code
1 Byte
33H
Read
ROM?
N
Y
From Memory Functions
Flow Chart (Figure 10)
Master TX ROM
Function Command
DS1921 TX
Presence Pulse
Master TX
Reset Pulse
Short
Reset Pulse?
N
Y
OD = 0
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
1)
2)
1) To be transmitted or received at Overdrive speed if
OD = 1.
2) The Presence Pulse will be short if OD = 1.
From Figure 13
2
nd
Part
From Figure 13
2
nd
Part
To Figure 13
2
nd
Part
To Figure 13
2
nd
Part