Intel IXP2800 and IXP2850 Network Processors
Electrical Specifications
Datasheet
123
4.4.14
Reset Timing
Table 64 shows the reset timing specifications for CLK_NRESET. The basic reset timing sequence
Table 63. JTAG AC Specifications
Symbol
Parameter
Minimum
Typical
Maximum
Unit
Notes
1, 2, 3, 4, 5,
6, 7, 8, 9
Tbscl
TCK low period
50
—
ns
Tbsch
TCK high period
50
—
ns
Tbsis
TDI, TMS setup to [TCr]
10
—
ns
Tbsih
TDI, TMS hold from [TCr]
10
—
ns
Tbsoh
TDO hold time
5
—
ns
Tbsod
TCf to TDO valid
—
40
ns
Tbsss
I/O signal setup to [TCr]
5
—
ns
Tbssh
I/O signal hold from [TCr]
20
—
ns
Tbsdh
Data output hold time
5
—
ns
Tbsdd
TCf to data output valid
—
40
ns
Tbsoe
TDO enable time
5
—
ns
Tbsoz
TDO disable time
—
40
ns
Tbsde
Data output enable time
5
—
ns
Tbsdz
Data output disable time
—
40
ns
Tbsr
Reset period
30
—
ns
Tbsrs
TMS setup to [TRr]
10
—
ns
Tberh
TMS hold from [TRr]
10
—
ns
1.
aaa Guaranteed by design.
2. Assumes a 25 pF load on TDO. Output timing derates at 0.072 ns/pF of extra load applied.
3. For correct data latching, the I/O signals (from the core and the pads) must be set up and held with respect to the rising edge
of TCK in the CAPTURE-DR state of the SAMPLE/PRELOAD and EXTEST instructions.
4. Assumes that the data outputs are loaded with the AC test loads.
5. TDO enable time applies when the TAP controller enters the Shift-DR or Shift-IR states.
6. TDO disable time applies when the TAP controller leaves the Shift-DR or Shift-IR states
7. Data output enable time applies when the boundary scan logic is used to enable the output drivers.
8. Data output disable time applies when the boundary scan logic is used to disable the output drivers.
9. TCK may be stopped indefinitely in either the low or high phase.
Table 64. Reset Timing Specification
Symbol
Parameter 1
1. Guaranteed by functional testing.
Minimum
Maximum
Unit
tRST
CLK_NRESET, must be asserted
prior to VDD being stable.
1—
ms
tSS
Configuration Strap Pins2 Setup
to NRESET
5
Reference Clock Cycles
(REF_CLK)3
tHS
Configuration Strap
Pins2 Hold
from NRESET
5
Reference Clock Cycles