Lucent Technologies DSP1611, Information Manual

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Information Manual DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
April 1998
Lucent Technologies Inc.
DRAFT COPY
10-1
10 Bit I/O Unit
The Bit I/O (BIO) Unit for the DSP1611, DSP1617, DSP1618, DSP1627, DSP1628, and DSP1629 provides eight
bidirectional pins for monitor or control functions. The pins are multiplexed with the PIO
1
/PHIF
2
and interrupt state
pins. The BIO features include:
Each pin can be an input or an output independent of the others and can be changed back and forth by the pro-
gram.
Data on inputs can be read directly into the DSP or can be compared with a stored pattern with or without
masking. Flags are set based on the result.
Data from the DSP can be placed directly on outputs, or the outputs can be toggled or left unchanged.
The BIO is mainly intended for status and control but is also useful for general data purposes.
This chapter describes the BIO hardware function and the software view including register encodings, sample pro-
grams, and pertinent instructions.
10.1 BIO Hardware Function
Figure 10-1 is the block diagram for the BIO. Eight bidirectional pins (IOBIT[7:0]) go off-chip from the BIO. The
interface to the internal part of the DSP is through the internal data bus (IDB) and the flags. Data move instructions
transfer information to and from the BIO control registers over the IDB. The flags are set based on tests done on
the data on the IOBIT input pins.
5-4198
Figure 10-1. BIO Block Diagram
Two registers (cbit and sbit) are the main components in the BIO. They are used for control of the unit and transfer
of data. The upper byte of the sbit register controls the direction of each pin independently of the others.
Section
10.1.1, BIO Configured as Inputs , and Section 10.1.2, BIO Configured as Outputs describe the BIO.
1.DSP1617 only.
2.DSP1611/18/27/28/29 only.
B I O
4
16
VE C[ 3:0] /I O BIT [7: 4]
MU X
MU X
FLAGS
DSP1611/17/18/27/28/29
PB[7:4]
IOBIT[7:0]
PB[7:4]/IOBIT[3:0]
VEC[3:0]
ioc (10)
ioc (12)
IDB