8

3492A–PLD–12/05

ATF1502BE

5.

Programming Methods

The ATF1502BE devices are In-System Programmable (ISP) or In-System Configurable (ISC)

devices utilizing the 4-pin JTAG protocol. This capability eliminates package handling normally

required for programming and facilitates rapid design iterations and field changes.

When using the ISP hardware or software to program the ATF1502BE 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 buried 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. ATF1502BE 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.

The AT1502BE device supports several configuration modes which gives designers several

unique options for programming.

The different modes of programming are:

• ISC – In System Configuration

• OTF – On-the-Fly Reconfiguration

• DRA – Direct Reconfiguration Access

5.1

In-System Configuration – ISC (Also Referred to as ISP)

This mode is the de-facto standard used to program the CPLD when it is attached to a PCB. The

term ISC can also be used interchangeably with ISP (In-system Programming). ISC or ISP elim-

inates the need for an external device programmer, and the devices can be soldered to a PCB

without being preprogrammed.

In the ISC mode, the logic operation of the ATF1502BE is halted and the embedded configura-

tion memory is programmed. The device is programmed by first erasing the configuration

memory in the CPLD and loading the new configuration data into the memory, which in-turn con-

figures the PLD for functional mode. When the device is in the ISC programming mode, all user

I/Os are held in the high impedance state.

The ISC mode is best suited for working with the ATF1502BE device in a design development or

production environment. Configuration of the ATF1502BE device done via a Download Cable

(see Figure 5-1 on page 8) is the default mode used to program the device in the ISC mode. In

this mode, the PC is typically the controlling device that communicates with the CPLD.

Figure 5-1.

Configuration of ATF1502BE Device Using a Download Cable

TCK

TDO

TMS

TDI

ATF1502BE

CPLD Device

2

4

6

8

10

1

3

5

7

9

JTAG

Connector

Connect

ISP Download

Cable to 10-pin

JTAG Header