15-2
LatticeECP2/M sysCONFIG Usage Guide
Configuration Pins
The LatticeECP2/M supports two types of configuration pins, dedicated and dual-purpose. The dedicated pins are
used exclusively for configuration; the dual-purpose pins, when not being used for configuration, are available as
extra I/O pins. If a dual-purpose pin is to be used both for configuration and as a general purpose I/O (GPIO) the
user must adhere to the following:
• The I/O type must remain the same, in other words if the pin is a 3.3V CMOS pin (LVCMOS33) during configura-
tion it must remain a 3.3V CMOS pin as a GPIO.
• The user must select the correct CONFIG_MODE setting and set the PERSISTENT bit to OFF in order to use
the dual-purpose sysCONFIG pins as GPIO after configuration. In ispLEVER
®
these preferences can be set in
the Design Planner. If you are using Lattice Diamond™ design software, select
Tools > Spreadsheet View
and
then select the
Global Preferences
tab in the Spreadsheet View.
• The user is responsible for insuring that no internal or external logic will interfere with device configuration.
Also, if slave parallel configuration mode is not being used then one or both of the parallel port chip selects (CSN,
CS1N) must be high or tri-state during configuration.
Programmable options control the direction and type of each dual-purpose configuration pin. These options are
controlled via pin preferences in Lattice ispLEVER and Diamond software, or as HDL source file attributes.
The LatticeECP2/M also supports ispJTAG for configuration, transparent read back, and JTAG testing. The follow-
ing sections describe the function of the various sysCONFIG and JTAG pins. Table 15-2 is provided for reference.
Table 15-2. Configuration Pins for the LatticeECP2/M
Pin Name
I/O Type
Pin Type
Mode Used
CFG[2:0]
Input, weak pull-up
Dedicated
All
PROGRAMN
Input, weak pull-up
Dedicated
All
INITN
Bi-Directional Open Drain, weak pull-up
Dedicated
All
DONE
Bi-Directional Open Drain with weak pull-
up, or Active Drive
Dedicated
All
CCLK
Input or Output
Dedicated
All
DI/CSSPI0N
2
Input, weak pull up
Dual-Purpose
Serial, SPI, SPIm
DOUT/CSON
2
Output
Dual-Purpose
Parallel, Serial, SPI
CSN
2
Input, weak pull-up
Dual-Purpose
Parallel
CS1N
2
Input, weak pull-up
Dual-Purpose
Parallel
WRITEN
2
Input, weak pull-up
Dual-Purpose
Parallel
BUSY/SISPI
2
Output, tri-state, weak pull-up
Dual-Purpose
Serial, SPI, SPIm
D[0]/SPIFASTN
2
Input or Output
Dual-Purpose
Parallel, SPI, SPIm
D[1:6]
2
Parallel
D[7]/SPID0
2
Parallel, SPI, SPIm
TDI
Input, weak pull-up
Dedicated
JTAG
TDO
Output, weak pull-up
Dedicated
JTAG
TCK
Input with Hysteresis
Dedicated
JTAG
TMS
Input, weak pull-up
Dedicated
JTAG
1. Weak pull-ups consist of a current source of 30µA to 150µA. The pull-ups for sysCONFIG dedicated and dual-purpose pins track V
CCIO8
;
the pull-ups for TDI, TDO, and TMS track V
CCJ
.
2. The sysCONFIG pins on the LatticeECP2M50/M70/M100 are dedicated sysCONFIG pins. The sysCONFIG output pins are actively driven
during normal device operation.