TMS320LF2407 Datasheet, PDF (51/106 Pages) Texas Instruments – DSP CONTROLLERS

TMS320LF2407, TMS320LF2406, TMS320LF2402
TMS320LC2406, TMS320LC2404, TMS320LC2402
DSP CONTROLLERS
SPRS094C – APRIL 1999 – REVISED OCTOBER 1999
digital I/O and shared pin functions
The ’240x has up to 41 general-purpose, bidirectional, digital I/O (GPIO) pins—most of which are shared
between primary functions and I/O. Most I/O pins of the ’240x are shared with other functions. The digital I/O
ports module provides a flexible method for controlling both dedicated I/O and shared pin functions. All I/O and
shared pin functions are controlled using eight 16-bit registers. These registers are divided into two types:
D Output Control Registers — used to control the multiplexer selection that chooses between the primary
function of a pin or the general-purpose I/O function.
D Data and Control Registers — used to control the data and data direction of bidirectional I/O pins.
description of shared I/O pins
The control structure for shared I/O pins is shown in Figure 16, where each pin has three bits that define its
operation:
D Mux control bit — this bit selects between the primary function (1) and I/O function (0) of the pin.
D I/O direction bit — if the I/O function is selected for the pin (mux control bit is set to 0), this bit determines
whether the pin is an input (0) or an output (1).
D I/O data bit — if the I/O function is selected for the pin (mux control bit is set to 0) and the direction selected
is an input, data is read from this bit; if the direction selected is an output, data is written to this bit.
The mux control bit, I/O direction bit, and I/O data bit are in the I/O control registers.
IOP DIR Bit
0 = Input
1 = Output
IOP Data Bit
(Read/Write)
In
Out
Primary
Function
0
1
MUX Control Bit
0 = I/O Function
1 = Primary Function
Primary
Function ^Pin
or I/O Pin
Figure 16. Shared Pin Configuration
A summary of shared pin configurations and associated bits is shown in Table 13.
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