13–2
Chapter 13: IEEE 1149.1 (JTAG) Boundary-Scan Testing for MAX II Devices
IEEE Std. 1149.1 BST Architecture
In addition to BST, you can use the IEEE Std. 1149.1 controller for in-system
programming for MAX II devices. MAX II devices support IEEE 1532 programming,
which utilizes the IEEE Std. 1149.1 Test Access Port (TAP) interface. However, this
chapter only discusses the BST feature of the IEEE Std. 1149.1 circuitry.
IEEE Std. 1149.1 BST Architecture
A MAX II device operating in IEEE Std. 1149.1 BST mode uses four required pins,
TDI, TDO, TMS, and TCK. Table 13–1 summarizes the functions of each of these pins.
MAX II devices do not have a TRSTpin.
Table 13–1. EEE Std. 1149.1 Pin Descriptions
Pin
Description
Function
TDI(1) Test data input
Serial input pin for instructions as well as test and
programming data. Data is shifted in on the rising edge of TCK.
TDO
Test data output
Serial data output pin for instructions as well as test and
programming data. Data is shifted out on the falling edge of
TCK. The pin is tri-stated if data is not being shifted out of the
device.
TMS (1) Test mode select
Input pin that provides the control signal to determine the
transitions of the TAP controller state machine. Transitions
within the state machine occur at the rising edge of TCK.
Therefore, TMSmust be set up before the rising edge of TCK.
TMSis evaluated on the rising edge of TCK.
TCK(2) Test clock input
The clock input to the BST circuitry. Some operations occur at
the rising edge, while others occur at the falling edge.
Notes to Table 13–1:
(1) The TDIand TMSpins have internal weak pull-up resistors.
(2) The TCKpin has an internal weak pull-down resistor.
The IEEE Std. 1149.1 BST circuitry requires the following registers:
■
■
■
The instruction register, which is used to determine the action to be performed and
the data register to be accessed.
The bypass register, which is a 1-bit-long data register used to provide a
minimum-length serial path between TDIand TDO.
The boundary-scan register that is a shift register composed of all the boundary-
scan cells of the device.
MAX II Device Handbook
© October 2008 Altera Corporation
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