EP80579 Datasheet, PDF (1721/1916 Pages) Intel Corporation – Intel® EP80579 Integrated Processor Product Line

Intel^® EP80579 Integrated Processor
46.0 ICH Design for Test
46.1
JTAG
The IICH in the EP80579 does not have a JTAG interface.
46.2
I/O Test Mode
46.2.1
Test Mode Entry Methods
Non-functional test modes are dedicated test modes where the chip is not operating in
its normal manner. This test mode includes Boundary scan. Functional test modes are
features built into the existing functional modes that allow the IICH to be optimally
tested and/or margined in its normal operating mode.
46.2.1.1
Non-Functional Test Mode Entry
This section covers the Non-functional Test Mode entry methods.
46.2.1.1.1 Serial Test Mode (STM) Entry
The Non-functional test mode is activated with the Serial Test Mode Entry. This method
uses a single test pin (DFXTEST#) to write to a test-mode command register or to read
from a test-mode status register.
DFXTEST_N pin on EP80579 is shared between IICH and IMCH. By default it works as
DFXTEST_N pin for IICH and if JTAG_INSTR_0x73 is set in the MCH, then it acts as
TESTNN pin for IMCH.
The protocol for this serial test mode entry is based on PCICLK and is depicted in
Table 46-1. For either a read or a write, an 18-bit serial command field is fed into the
test pin, prefaced with a ‘0’ as the start bit (the idle condition of the test pin must be a
logic-high). For a write, the 18-bit command field is followed by 32 bits of write data,
which is fed into the appropriate test-mode command register. For a read, the 18-bit
command field is followed by one clock of turn-around, followed by the test-pin driving
out 32 bits of read data. Figure 46-1 and Figure 46-2 demonstrate the timing of the
Serial Test Mode Entry read and write cycles. It is important that test modes are not
activated until after the entire data field has been written. It is also important that if a
register is read, that its value is sampled at the end of the turn-around cycle. All serial
values are put out MSB-first.
August 2009
Order Number: 320066-003US
Intel^® EP80579 Integrated Processor Product Line Datasheet
1721