Echelon Series 6000 Chip databook - Manual (Page 121)

Example: The following I/O object types can be combined for a Neuron Chip or Smart
Transceiver:
• 1 parallel I/O object type (on IO_0..IO10)
OR
• 1 muxbus I/O object type (on IO_0..IO10)
OR
• A combination of any or all of the other I/O models A through E shown in Table 34:
Table 34. Example I/O Model Combinations
A B C D E
1 to 4
timer/counter
inputs
(multiplexed on
IO_4, IO_5,
IO_6, IO_7),
including
quadrature
input on IO_6
1 timer/counter
input (on IO_4),
including
quadrature
input on IO_4
1 neurowire
I/O object (on
IO_8, IO_9,
IO_10) and 1 of
IO_0 ... IO_7
Any direct I/O
object type on
any pin (IO_0
through IO_10)
A bit I/O object
on IO_11
OR OR OR
1 timer/counter
output (on IO_0)
1 timer/counter
output (on IO_1)
1 serial I/O
object type (on
IO_8, IO_10)
Hardware Considerations
For a description of the electrical characteristics of the I/O pins, see Characteristics of the
Digital Pins or the appropriate Series 3100, Series 5000, or Series 6000 device data sheet.
Pins that are configured as outputs can also be read as inputs, returning the value that was
last written to the pin. In addition, an application program can optionally specify the initial
values of digital outputs.
For Series 3100 devices, pins IO4 – IO7 and IO11 have optional pull-up current sources that
act as pull-up resistors. You use a Neuron C compiler directive (#pragma
enable_io_pullups) to enable these pull-ups. Also for Series 3100 devices, pins IO0 – IO3
have high current-sink capability (20 mA); the other pins have standard current-sink
capability.
For Series 3100 FT Smart Transceivers, the I/O pull-ups are enabled during the stack
initialization and built-in self-test (BIST) task (see the FT 3120 / FT 3150 Smart
Transceiver Data Book for more information about the stack initialization and BIST task).
For Series 6000 devices, the I/O pins do not have configurable pull-ups or high current-sink
capability. If your I/O circuitry requires pull-up resistors, you must add them to the
hardware design for the device. The I/O pins on a Series 6000 device have an 8 mA current
Series 6000 Chip Data Book 109