cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 180

• Manufacturer Part Number: cs5535
• Description: Geode Cs5535 Companion Multi-function South Bridge
• Manufacturer: National Semiconductor Corporation

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TAP Controller Functional Description
22:17
15:10
Bit
9:7
2:0
23
16
6
5
4
3
Name
TAPSCAN
USER[5:0]
bistEnable[3]
RSVD
bistEnable[2:0]
RSVD
forceDis
selectJtagOut
selectJtagIn
OP[2:0]
Description
TAP Scan. (Also USER[6].) This is a user bit added by National. Low indicates that an
internal scan chain will be accessed by the TAP.
User Bits 5 through 0. User bits used to identify an internal scan chain or, if bit 23 is
high, to access a special internal DR.
BIST Enable Bit 3. Works in conjunction with bits [9:7]. See bits [9:7] description for
decode.
Reserved. Should always be high.
BIST Enable Bits 2 through 0. Works in conjunction with bit 16.
0000:
0010:
0100:
0110:
0001:
0011:
0101:
0111:
1000:
1010:
1100:
1110:
1011:
1001:
1101:
1111:
Reserved. Should always be high.
Force Disable. Active low bit that places all output pins in TRI-STATE mode. See
TRISTATE for details.
Select JTAG Output. Active low bit that allows boundary scan cells to control pads.
Select JTAG Output. Active low bit that allows boundary scan cells to drive data into
core logic of chip.
Operation Bits 2 through 0. Selects for how the JTAG chains are wired together.
000:
001:
010:
011:
100:
101:
110:
111:
Table 4-39. TAP Controller Instruction Bits
bistEn12
bistEn11
bistEn10
bistEn9
bistEn8
bistEn7
bistEn6
bistEn5
bistEn4
bistEn3
bistEn2
bistEn1
bistEn0
Does nothing [normally used for logic BIST]
Parallel scan
Scan through TAP
TDI -> Boundary Scan -> TDO
TDI -> Boundary Scan -> Internal Scan -> Device ID -> Bypass -> TDO
TDI -> Internal Scan -> TDO
TDI -> Boundary Scan -> Internal Scan -> Device ID -> Bypass -> TDO
TDI -> Internal Scan -> TDO
TDI -> Internal Data Register -> TDO
TDI -> Device ID -> TDO
TDI -> Bypass -> TDO
(Continued)
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