Altera Corporation 11
Configuration Devices for A CEX, APEX, FLEX & Mercury Devices Data Sheet
ACEX 1K, APEX 20K, FLEX 10K, FLEX 6000 & Mercury Device
Configuration with Multiple EPC2 or EPC1 Configuration Devices
When configuration data for ACEX 1K, APEX 20K, FLE X 10K, FLEX 6000,
or Mercury devices exceeds the capacity of a singl e EPC2 or E PC1 devi ce,
multiple EPC2 or EPC1 devices can be cascaded together. (The EPC14 41
device does not support data cascading.) If multiple EPC2 or EPC1
devices are required, the nCASC and nCS pins provide han dshaking
between the dev ices.
When configuring ACEX 1K, APEX 20K, FLEX 10K, FLEX 6000, or
Mercury devices with cascaded EPC2 or EPC1 dev ices, the position of the
EPC2 or EPC1 device in the cha in determines its operatio n. When the first
or maste r device in a config uration device c hain is powered-up or reset
and the nCS pin is driven low, the master device controls configuration.
The master devic e suppl ies al l clock pulses to one or m ore AC EX, APEX ,
FLEX, or Mercu ry devic es and to an y subsequ en t slave dev ice s during
configurat ion. The master EPC2 or EPC1 device also provides the first
stream of data to the ACEX, APEX, FLEX, or Mercury devices during
multi-device configurat ion. After the master EPC2 or EPC1 device
finishes sending configuration data, the master EPC2 or EPC1 device
drives its nCASC pin low, whic h drives the nCS pin of th e firs t slave EP C2
or EPC1 device low. This action causes the slave EPC2 or EPC1 device to
send configuration data to the ACEX, APEX, FLEX, or Mercury devices.
The maste r EPC2 or E PC1 device c locks all sub sequent sla ve devices u ntil
configuration is complete. Once all configuration data is transferred and
the nCS pin on the master EPC2 or EPC1 device is driven high by the
ACEX, APEX, FLEX, or Mercury device’s CONF_DONE pin, the m aster
EPC2 or EPC 1 device clocks 16 additional cycles to initialize the ACEX,
APEX, FLEX, or Mercury device(s). Th e master EPC2 or EPC1 devic e then
goes into zero-power (idle) state. If nCS on the master EPC2 or EPC1
device i s driven high before all conf iguration d ata is tra nsferred, or if nCS
is not driven high after all configuration data is transferred, the master
EPC2 or EPC1 device drives t he ACEX, AP EX, FLEX, or M ercury devic e’s
nSTATUS pin low, indicating a configuration error.
Configuration automatically restarts if the project is compiled with the
Auto-Restart Configuration on Frame Error option turned on in the
MAX+PLUS II software’s Global Proje ct Devic e Options dialog box
(Assign menu).
Figure 5 shows an AC EX 1K, APE X 20K, FLEX 10K, FLE X 60 00, or
Mercury device configured with two EPC2 or EPC1 devices. Additional
EPC2 or EPC1 devices can be added by connecting nCASC to nCS of the
subsequen t slave EP C2 or EPC1 dev ice in the chain and connec ting DCLK,
DATA, and OE in parallel.