8

1615J–PLD–01/06

ATF1502ASV

Atmel provides ISP hardware and software to allow programming of the ATF1502ASV via the

PC. ISP is performed by using either a download cable, a comparable board tester or a simple

microprocessor interface.

When using the ISP hardware or software to program the ATF1502ASV devices, four I/O pins

must be reserved for the JTAG interface. However, the logic features that the macrocells have

associated with these I/O pins are still available to the design for burned logic functions.

To facilitate ISP programming by the Automated Test Equipment (ATE) vendors. Serial Vector

Format (SVF) files can be created by Atmel-provided software utilities.

ATF1502ASV devices can also be programmed using standard third-party programmers. With a

third-party programmer, the JTAG ISP port can be disabled, thereby allowing four additional I/O

pins to be used for logic.

Contact your local Atmel representatives or Atmel PLD applications for details.

6.1

ISP Programming Protection

The ATF1502ASV has a special feature that locks the device and prevents the inputs and I/O

from driving if the programming process is interrupted for any reason. The inputs and I/O default

to high-Z state during such a condition. In addition, the pin-keeper option preserves the previous

state of the input and I/O PMS during programming.

All ATF1502ASV devices are initially shipped in the erased state, thereby making them ready to

use for ISP.

Note:

For more information refer to the “Designing for In-System Programmability with Atmel CPLDs”

application note.

7.

JTAG-BST/ISP Overview

The JTAG boundary-scan testing is controlled by the Test Access Port (TAP) controller in the

ATF1502ASV. The boundary-scan technique involves the inclusion of a shift-register stage

(contained in a boundary-scan cell) adjacent to each component so that signals at component

boundaries can be controlled and observed using scan testing methods. Each input pin and I/O

pin has its own boundary-scan cell (BSC) to support boundary-scan testing. The ATF1502ASV

does not include a Test Reset (TRST) input pin because the TAP controller is automatically

reset at power-up. The five JTAG modes supported include: SAMPLE/PRELOAD, EXTEST,

BYPASS, IDCODE and HIGHZ. The ATF1502ASV’s ISP can be fully described using JTAG’s

BSDL as described in IEEE Standard 1149.1b. This allows ATF1502ASV programming to be

described and implemented using any one of the third-party development tools supporting this

standard.

The ATF1502ASV has the option of using four JTAG-standard I/O pins for boundary-scan test-

ing (BST) and in-system programming (ISP) purposes. The ATF1502ASV is programmable

through the four JTAG pins using the IEEE standard JTAG programming protocol established by

IEEE Standard 1149.1 using 5V TTL-level programming signals from the ISP interface for in-

system programming. The JTAG feature is a programmable option. If JTAG (BST or ISP) is not

needed, then the four JTAG control pins are available as I/O pins.

7.1

JTAG Boundary-scan Cell (BSC) Testing

The ATF1502ASV contains up to 32 I/O pins and four input pins, depending on the device type

and package type selected. Each input pin and I/O pin has its own boundary-scan cell (BSC) in