X9251-2.7 INTERSIL [Intersil Corporation], X9251-2.7 Datasheet - Page 9

• Manufacturer Part Number: X9251-2.7
• Description: Single Supply/Low Power/256-Tap/SPI Bus
• Manufacturer: INTERSIL [Intersil Corporation]

Figure 2. Two-Byte Instruction Sequence
Figure 3. Three-Byte Instruction Sequence SPI Interface; Write Case
Figure 4. Three-Byte Instruction Sequence SPI Interface, Read Case
S0
SCK
SI
SCK
SI
CS
CS
ID3 ID2 ID1 ID0
ID3 ID2 ID1 ID0
0
0
SCK
Device ID
CS
SI
Device ID
1
1
0
0
1
1
ID3 ID2 ID1 ID0
0
0
0
0
0
9
Device ID
0
0
0
0
1
Internal
Address
A1 A0
Internal
Address
A1 A0
0
1
0
0
I3
I3 I2
Instruction
0
0
Opcode
Instruction
Opcode
I2
A1 A0
Address
Internal
I1
I1 I0
X9251
I0
Register
Address
I3
Register
Address
RB RA
RB RA
Instruction
Opcode
I2
DCP/WCR
DCP/WCR
P1
P1
I1
Address
Address
P0
P0
I0
Address
Register
RB RA
D7 D6 D5 D4 D3 D2 D1 D0
D7 D6 D5 D4 D3 D2 D1 D0
X
Data for WCR[7:0] or DR[7:0]
X
Data Register Bit [7:0]
DCP/WCR
Address
P1
X
Don’t Care
WCR[7:0]
P0
X
or
X
X
X
X
September 14, 2005
FN8166.2