EP3C16F256I7 Altera, EP3C16F256I7 Datasheet - Page 319

• Manufacturer Part Number: EP3C16F256I7
• Description: Cyclone III
• Manufacturer: Altera

Altera Corporation-Preliminary
March 2007
reconfiguration, you must disengage the active configuration (AS, and
AP) controllers when active configuration is interrupted. You must issue
the ACTIVE_DISENGAGE instruction alone or prior to CONFIG_IO
instruction if the JTAG_PROGRAM instruction is to be issued later (refer to
Table 10–18
AS controller into the "idle" state. The active configuration controller will
be enabled when Cyclone III devices completes reconfiguration using
JTAG_PROGRAM instruction.
1
If reconfiguration after interruption is done using native modes (rather
than using JTAG_PROGRAM), then it is not necessary to issue
ACTIVE_DISENGAGE instruction prior to CONFIG_IO. You can initiate
reconfiguration by either pulling nCONFIG pin low for at least 500 ns, or
issuing PULSE_NCONFIG instruction. In the case ACTIVE_DISENGAGE
instruction was issued and JTAG_PROGRAM instruction is unsuccessful to
usermode, you must issue the ACTIVE_ENGAGE instruction to reactivate
the active configuration (AS, and AP) controller. Issuing
ACTIVE_ENGAGE instruction also will trigger reconfiguration in native
modes, therefore it is not necessary to pull nCONFIG pin low or issuing
PULSE_NCONFIG instruction.
ACTIVE_DISENGAGE
The ACTIVE_DISENGAGE is a unique JTAG instruction on Cyclone III
devices that places the active configuration (AS, and AP) controllers into
an "idle" state prior to JTAG programming. The active configuration
controllers are the AS controller when the MSEL pins are set to AS
configuration scheme, and the AP controller when the MSEL pins are set
to AP configuration scheme. The two purposes of placing the active
controllers in an idle state is to ensure that they are not trying to configure
the device in their respective native modes during JTAG programming
and to allow the controllers to properly recognize a successful JTAG
programming that results in the device reaching usermode.
The new ACTIVE_DISENGAGE instruction is required before JTAG
Programming regardless of the current state of the Cyclone III device if
the MSEL pins are set to an active configuration mode. The
ACTIVE_DISENGAGE instruction can be issued during a passive
configuration scheme (PS, or FPP), it will just have no effect on the
Cyclone III device. Similarly, the CONFIG_IO instruction can be issued
after an ACTIVE_DISENGAGE instruction, but is no longer required to
properly halt native configuration. Refer to
While executing the CONFIG_IO instruction, all user IOs are tri-
stated.
). This puts the AP controller into the "chill-out" state, and the
Cyclone III Device Handbook, Volume 1
Table 10–18
Cyclone III JTAG Instructions
for a summary of
10–83