DATA SHEET
µ
PD72042A, 72042B
LSI DEVICES FOR Inter Equipment Bus
TM
(IEBus
TM
)
PROTOCOL CONTROL
MOS INTEGRATED CIRCUIT
The
µ
PD72042A and
µ
PD72042B are microcomputer peripheral LSI devices for IEBus protocol control.
The
µ
PD72042A and
µ
PD72042B perform all the processing required for layers 1 and 2 of the IEBus. The devices
incorporate large transmission and reception buffers, allowing the microcomputer to perform IEBus operations without
interruption. They also contain an IEBus driver and receiver, allowing them to directly connected to the bus directly.
FEATURES
•
Control of layers 1 and 2 of the IEBus protocol
• Support of a multi-master scheme
• Broadcast function
• Two communication modes having different
transmission speeds can be selected.
When operating
at 6 MHz
Mode 0
Mode 1
q
q
•
Microcomputer interface
Three-/two-wire serial I/O
• Transfer starting with MSB
• Transfer starting with LSB
watchdog timer.
:
µ
PD72042A
:
µ
PD72042B
•
Program crashes can be detected by means of a
•
Low power consumption (standby mode):
50
µ
A (max)
When operating
at 6.29 MHz
Approx. 4.1 Kbps
Approx. 18 Kbps
Approx. 3.9 Kbps
Approx. 17 Kbps
•
Oscillator frequency (f ):
X
6 MHz, 6.29 MHz
• frequency accuracy:
±1.5%
5 V
±10%
•
Operating voltage:
Built-in IEBus driver and receiver
Transmission and reception buffers
Transmission buffer
Reception buffer
: 33 bytes, FIFO
: 40 bytes, FIFO (capable of
holding more than one frame
of reception data.)
ORDERING INFORMATION
Part number
Package
16-pin plastic SOP (375 mil)
16-pin plastic SOP (375 mil)
Starting with MSB/LSB
MSB
LSB
µ
PD72042AGT
µ
PD72042BGT
The information in this document is subject to change without notice.
Document No. S13990EJ2V0DS00 (2nd edition)
(Previous No. ID-3649)
Date Published January 1999 N CP(N)
Printed in Japan
The mark
shows major revised points.
©
1995
µ
PD72042A, 72042B
CONTENTS
1. PIN FUNCTIONS .............................................................................................................................
1.1
PIN FUNCTIONS .....................................................................................................................................
6
6
2. IEBus OPERATION .........................................................................................................................
2.1
2.2
OVERVIEW ..............................................................................................................................................
IEBus COMMUNICATION PROTOCOL ................................................................................................
2.2.1
2.2.2
2.2.3
2.2.4
2.3
2.4
2.5
Bus Mastership Determination (Arbitration) ...............................................................................
Communication Mode .................................................................................................................
Communication Address .............................................................................................................
Broadcast .....................................................................................................................................
8
8
9
10
10
11
11
11
17
21
TRANSMISSION PROTOCOL ...............................................................................................................
TRANSMISSION DATA (CONTENTS OF THE DATA FIELD) .............................................................
BIT FORMAT ...........................................................................................................................................
3. MICROCOMPUTER INTERFACE .................................................................................................. 22
3.1
3.2
TRANSFER METHOD ............................................................................................................................
DATA TRANSFER FORMAT ..................................................................................................................
3.2.1
3.2.2
3.3
3.4
3.5
Three-Wire Data Transfer (SEL = 1) ..........................................................................................
Two-Wire Data Transfer (SEL = 0) .............................................................................................
22
23
23
26
29
30
30
CONNECTION TO A MICROCOMPUTER .............................................................................................
STANDBY MODE SETTING AND CANCELLATION ............................................................................
RESET MODE SETTING AND CANCELLATION .................................................................................
4. REGISTERS .................................................................................................................................... 31
5. EXAMPLE TIMINGS FOR COMMUNICATION .............................................................................. 61
6. EXAMPLE MICROCOMPUTER PROCESSING FLOW ................................................................ 69
6.1
6.2
6.3
6.4
COMMUNICATION FLAGS ....................................................................................................................
MAIN ROUTINE ......................................................................................................................................
INTERRUPT ROUTINE ...........................................................................................................................
PROCESSING ROUTINES .....................................................................................................................
6.4.1
6.4.2
6.4.3
6.4.4
6.4.5
6.4.6
6.4.7
Communication Flag Initialization Routine .................................................................................
Command Processing Routine ...................................................................................................
Master Communication Processing Routine ..............................................................................
Slave Data Transmission Processing Routine ...........................................................................
Transmission Processing Routine ..............................................................................................
Reception Processing Routine ...................................................................................................
70
71
72
74
74
75
75
79
82
83
µ
PD72042A or
µ
PD72042B Initial Setting Routine .................................................................... 74
7. ELECTRICAL CHARACTERISTICS .............................................................................................. 84
8. PACKAGE DRAWING ..................................................................................................................... 88
4
DATA SHEET S13990EJ2V0DS00
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