Chapter 9: Configuration, Design Security, and Remote System Upgrades in the Cyclone III Device Family
Configuration Features
9–63
■
To allow the controllers to properly recognize a successful JTAG programming
that results in the device reaching user mode
The
ACTIVE_DISENGAGE
instruction is required before JTAG programming regardless
of the current state of the Cyclone III device family if the MSEL pins are set to an
active configuration scheme (AS or AP). If the
ACTIVE_DISENGAGE
instruction is issued
during a passive configuration scheme (PS or FPP), it has no effect on the Cyclone III
device family. Similarly, the
CONFIG_IO
instruction is issued after an
ACTIVE_DISENGAGE
instruction, but is no longer required to properly halt
configuration.
lists the required, recommended, and optional instructions
for each configuration mode. The ordering of the required instructions is a hard
requirement and must be met to ensure functionality.
Table 9–20. JTAG Programming Instruction Flows
Configuration Scheme and Current State of the Cyclone III Device
Prior to User Mode
(Interrupting
Configuration)
PS
FACTORY
ACTIVE_DISENGAGE
CONFIG_IO
Other JTAG instructions
JTAG_PROGRAM
CHECK_STATUS
JTAG_STARTUP
JTAG TAP Reset/ other instruction
Notes to
(1) “R” indicates that the instruction is required to be executed before the next instruction, “O” indicates the optional instruction, “Rc” indicates
the recommended instruction, and “NA” indicates that the instruction is not allowed to be executed in this mode.
(2) AP configuration is for Cyclone III devices only.
JTAG Instruction
User Mode
AP
Power Up
AP
FPP
NA
O
Rc
O
R
Rc
R
R
AS
NA
R
O
O
R
Rc
R
R
PS
NA
O
O
O
R
Rc
R
R
FPP
NA
O
O
O
R
Rc
R
R
AS
NA
O
O
O
R
Rc
R
R
PS
R
O
NA
O
R
Rc
R
R
FPP
R
O
NA
O
R
Rc
R
R
AS
R
R
NA
O
R
Rc
R
R
AP
NA
O
Rc
O
R
Rc
R
R
NA
R
O
O
R
Rc
R
R
NA
R
O
O
R
Rc
R
R
NA
R
NA
O
R
Rc
R
R
In AS or AP configuration schemes, the
ACTIVE_DISENGAGE
instruction puts the active
configuration controllers into idle state. If a successful JTAG programming is
executed, the active controllers are automatically re-engaged after user mode is
reached using JTAG programming. This causes the active controllers to transition to
their respective user mode states.
If JTAG programming fails to get the Cyclone III device family to enter user mode and
re-engage active programming, there are available methods to achieve this for the AS
or AP configuration schemes:
■
When in the AS configuration scheme, you can re-engage the AS controller by
moving the JTAG TAP controller to the reset state or by issuing the
ACTIVE_ENGAGE
instruction.
When in the AP configuration scheme, the only way to re-engage the AP controller
is to issue the
ACTIVE_ENGAGE
instruction. In this case, asserting the
nCONFIG
pin
does not re-engage either active controller.
■
August 2012
Altera Corporation
Cyclone III Device Handbook
Volume 1
ALTERA [ ALTERA CORPORATION ]
