isppac-powr1220at8 Lattice Semiconductor Corp., isppac-powr1220at8 Datasheet - Page 43

• Manufacturer Part Number: isppac-powr1220at8
• Description: In-system Programmable Power Supply Monitoring, Sequencing And Margining Controller
• Manufacturer: Lattice Semiconductor Corp.

Lattice Semiconductor
Figure 1-35. ispPAC-POWR1220AT8 TDI/ATDI Pin Selection Diagram
Table 1-12 shows in truth table form the same conditions required to select either TDI or ATDI as in the logic dia-
gram found in Figure 1-35.
Table 1-12. ispPAC-POWR1220AT8 ATDI/TDI Selection Table
Please refer to the Lattice application note AN6068, Programming the ispPAC-POWR1220AT8 in a JTAG Chain
Using ATDI. The application note includes specific SVF code examples and information on the use of Lattice
design tools to verify device operation in alternate TDI mode.
VCCPROG Power Supply Pin
Because the VCCPROG pin directly powers the on-chip programming circuitry, the ispPAC-POWR1220AT8 device
can be programmed by applying power to the VCCPROG pin (without powering the entire chip though the VCCD
and VCCA pins). In addition, to enable the on-chip JTAG interface circuitry, power should be applied to the VCCJ
pin.
When the ispPAC-POWR1220AT8 is using the VCCPROG pin, its VCCD and VCCA pins can be open or pulled low.
Additionally, other than JTAG I/O pins, all digital output pins are in Hi-Z state, HVOUT pins configured as MOSFET
driver are driven low, and all other inputs are ignored.
To switch the power supply back to VCCD and VCCA pins, one should turn the VCCPROG supply and VCCJ off
before turning the regular supplies on. When VCCD and VCCA are turned back on for normal operation,
VCCPROG should be left floating.
TDISEL Pin
H
H
L
TDISEL
ATDI
TDI
JTAG State Machine
Test-Logic-Reset
1
0
Test-Logic-Reset
Yes
No
X
Q
CLR
SET
ispPAC-POWR1220AT8
TMS
1-43
JTAG
TCK
Loaded at Update-IR
IDCODE Commands
IDCODE Instructions
Loaded at Update-IR
4 Consecutive
4 Consecutive
ispPAC-POWR1220AT8 Data Sheet
Yes
No
X
TDO
ATDI (TDI Disabled)
TDI (ATDI Disabled)
ATDI (TDI Disabled)
Data Input Pin
Active JTAG