for Brushed Servo and Brushless Servo Motion Control
Performance Motion Devices, Inc.
55 Old Bedford Road
Lincoln, MA 01773
Revision 1.8, October 2003
NOTICE
This document contains proprietary and confidential information of Performance Motion Devices,
Inc., and is protected by federal copyright law. The contents of this document may not be disclosed
to third parties, translated, copied or duplicated in any form, in whole or in part, without the express
written permission of PMD.
The information contained in this document is subject to change without notice. No part of this
document may be reproduced or transmitted in any form, by any means, electronic or mechanical,
for any purpose, without the express written permission of PMD.
Copyright 1998, 1999, 2000 by Performance Motion Devices, Inc.
Navigator and C-Motion are trademarks of Performance Motion Devices, Inc
Warranty
PMD warrants performance of its products to the specifications applicable at the time of sale in
accordance with PMD's standard warranty. Testing and other quality control techniques are utilized
to the extent PMD deems necessary to support this warranty. Specific testing of all parameters of
each device is not necessarily performed, except those mandated by government requirements.
Performance Motion Devices, Inc. (PMD) reserves the right to make changes to its products or to
discontinue any product or service without notice, and advises customers to obtain the latest version
of relevant information to verify, before placing orders, that information being relied on is current
and complete. All products are sold subject to the terms and conditions of sale supplied at the time
of order acknowledgement, including those pertaining to warranty, patent infringement, and
limitation of liability.
Safety Notice
Certain applications using semiconductor products may involve potential risks of death, personal
injury, or severe property or environmental damage. Products are not designed, authorized, or
warranted to be suitable for use in life support devices or systems or other critical applications.
Inclusion of PMD products in such applications is understood to be fully at the customer's risk.
In order to minimize risks associated with the customer's applications, adequate design and operating
safeguards must be provided by the customer to minimize inherent procedural hazards.
Disclaimer
PMD assumes no liability for applications assistance or customer product design. PMD does not
warrant or represent that any license, either express or implied, is granted under any patent right,
copyright, mask work right, or other intellectual property right of PMD covering or relating to any
combination, machine, or process in which such products or services might be or are used. PMD's
publication of information regarding any third party's products or services does not constitute PMD's
approval, warranty or endorsement thereof.
Five booklets containing physical and electrical characteristics, timing diagrams, pinouts, and pin
descriptions of each series:
MC2100 Series, for brushed servo motion control (MC2100TS);
MC2300 Series, for brushless servo motion control (MC2300TS);
MC2400 Series, for microstepping motion control (MC2400TS);
MC2500 Series, for stepping motion control (MC2500TS);
MC2800 Series, for brushed servo and brushless servo motion control (MC2800TS).
How to install and configure the DK2000 developer’s kit PC board.
MC2800 Technical Specifications
v
MC2800 Technical Specifications
vi
Table of Contents
Warranty...................................................................................................................................................... iii
Safety Notice ................................................................................................................................................ iii
Disclaimer..................................................................................................................................................... iii
Related Documents....................................................................................................................................... v
Table of Contents........................................................................................................................................ vii
1 The Navigator Family ............................................................................................................................... 9
Parallel word device input
Parallel communication
Serial communication
Diagnostic port
S-curve profiling
Electronic gearing
On-the-fly changes
Directional limit switches
Programmable bit output
Software-invertable
signals
PID servo control
Feedforward (accel & vel)
Derivative sampling time
Data trace/diagnostics
PWM output
This manual describes the operational characteristics of the MC2840 and MC2820 Motion
Processors from PMD. These devices are members of PMD’s second-generation motion processor
family, which consists of 14 separate products organized into 5 series.
Each of these devices is a complete chip-based motion processor. They provide trajectory
generation and related motion control functions. Depending on the type of motor controlled they
provide servo loop closure, on-board commutation for brushless motors, and high speed pulse and
direction outputs. Together these products provide a software-compatible family of dedicated
motion processors that can handle a large variety of system configurations.
Each of these chips utilize a similar architecture, consisting of a high-speed computation unit, along
with an ASIC (Application Specific Integrated Circuit). The computation unit contains special onboard hardware that makes it well suited for the task of motion control.
Along with similar hardware architecture these chips also share most software commands, so that
software written for one chipset may be re-used with another, even though the type of motor may be
different.
Each chipset consists of two PQFP (Plastic Quad Flat Pack) ICs: a 100-pin Input/Output (I/O)
chip, and a 132-pin Command Processor (CP) chip.
Four of the series in the Navigator family are designed for a particular type of motor or control
scheme. The fifth allows the user to control 2 servo motor types (brushed and brushless). Here is a
summary description of each series.
Family Summary
MC2100 Series (MC2140, MC2120, MC2110) – This series outputs motor commands in either
Sign/Magnitude PWM or DAC-compatible format for use with brushed servo motors, or with
brushless servo motors having external commutation.
MC2300 Series (MC2340, MC2320, MC2310) – This series outputs sinusoidally or 6-step
commutated motor signals appropriate for driving brushless motors. Depending on the motor type,
the output is a two-phase or three-phase signal in either PWM or DAC-compatible format.
MC2400 Series (MC2440, MC2420, MC2410) – This series provides microstepping signals for
stepping motors. Two phased signals per axis are generated in either PWM or DAC-compatible
format.
MC2500 Series (MC2540, MC2520, MC2510) – These chipsets provide high-speed pulse and
direction signals for stepping motor systems.
MC2800 Series (MC2840, MC2820) – This series outputs sinusoidally or 6-step commutated motor
signals appropriate for driving brushless servo motors as well as PWM or DAC- compatible outputs
for driving brushed servo motors.
MC2800 Technical Specifications
10
2 Functional Characteristics
2.1 Configurations, parameters, and performance
Available configurations 4 axes (MC2840) or 2 axes (MC2820)
Operating modes Closed loop (motor command is driven from output of servo filter)
Open loop (motor command is driven from user-programmed register)
Communication modes 8/8 parallel (8 bit external parallel bus with 8 bit internal command word size)
8/16 parallel (8 bit external parallel bus with 16 bit internal command word size)
16/16 parallel (16 bit external parallel bus with 16 bit internal command word
size)
Point to point asynchronous serial
Multidrop asynchronous serial
Serial port baud rate range 1,200 baud to 416,667 baud
Position range -2,147,483,648 to +2,147,483,647 counts
Velocity range -32,768 to +32,767 counts/sample with a resolution of 1/65,536 counts/sample
Acceleration/deceleration
ranges
Jerk range 0 to ½ counts/sample3, with a resolution of 1/4,294,967,296 counts/sample3
Profile modes S-curve point-to-point (Velocity, acceleration, jerk, and position parameters)
Electronic gear ratio range -32,768 to +32,767 with a resolution of 1/65,536 (negative and positive direction)
Filter modes Scalable PID + Velocity feedforward + Acceleration feedforward + Bias. Also
Filter parameter resolution 16 bits
Position error tracking Motion error window (allows axis to be stopped upon exceeding programmable
Motor output modes PWM (10-bit resolution at 20 kHz)
Commutation rate 20kHz for MC2820, 10kHz for MC2840
Maximum encoder rate Incremental (up to 5 Mcounts/sec)
Parallel encoder word size 16 bits
Parallel encoder read rate
Hall sensor inputs 3 Hall effect inputs per axis (TTL level signals)
Servo loop timing range
-32,768 to +32,767 counts/sample2 with a resolution of 1/65,536 counts/sample2
Trapezoidal point-to-point (Velocity, acceleration, deceleration, and position
parameters)
Velocity-contouring (Velocity, acceleration, and deceleration parameters)
Electronic Gear (Encoder or trajectory position of one axis used to drive a second
axis. Master and slave axes and gear ratio parameters)
includes integration limit, settable derivative sampling time, and output motor
command limiting
window)
Tracking window (allows flag to be set if axis exceeds a programmable position
window)
Axis settled (allows flag to be set if axis exceeds a programmable position
window for a programmable amount of time after trajectory motion is compete)
DAC (16 bits)
Parallel-word (up to 160 Mcounts/sec)
20 kHz (reads all axes every 50 µsec)
153.6 µsec to 32.767 milliseconds
MC2800 Technical Specifications
11
Minimum servo loop time
Multi-chip synchronization
Limit switches 2 per axis: one for each direction of travel
Position-capture triggers 2 per axis: index and home signals
Other digital signals (per axis) 1 AxisIn signal per axis, 1 AxisOut signal per axis
Software-invertable signals Encoder A, Encoder B, Index, Home, AxisIn, AxisOut, PositiveLimit,
Analog input 8 10-bit analog inputs
User defined discrete I/O 256 16-bit wide user defined I/O
RAM/external memory support 65,536 blocks of 32,768 16 bit words per block. Total accessible memory is
Trace modes one-time
Max. number of trace variables 4
Number of traceable variables 27
Number of host instructions 152
153.6 µsec per enabled axis
<10µsec difference between master and slave servo cycle
MC28x3 chipset only
NegativeLimit, HallA, HallB, HallC (all individually programmable per axis)
2,147,483,648 16 bit words
continuous
MC2800 Technical Specifications
12
2.2 Physical characteristics and mounting dimensions
2.2.1 CP chip
All dimensions are in inches (with millimeters in brackets).
A 3.40
A1 0.25 0.33
A2 2.55 2.80 3.05
b 0.22 0.38
c 0.13 0.23
D 22.95 23.20 23.45
D1 19.90 20.00 20.10
E 16.95 17.20 17.45
E1 13.90 14.00 14.01
e 0.65 BSC
L 0.73 0.88 1.03
ccc 0.10
theta 0° 7°
Nominal
(mm)
Maximum
(mm)
MC2800 Technical Specifications
14
2.3 Environmental and electrical ratings
All ratings and ranges are for both the I/O and CP chips.
Storage Temperature (T
Operating Temperature (T
Power Dissipation (P
Nominal Clock Frequency (F
Supply Voltage limits (V
)
s
)
a
) 600 mW (I/O and CP combined)
d
) 40.0 MHz
clk
) -0.3V to +7.0V
cc
Supply Voltage operating range (V
* An industrial version with an operating range of -40°C to 85°C is also available. Please contact
PMD for more information.
2.4 System configuration
The following figure shows the principal control and data paths in an MC2800 system.
Host
Parallel port
System clock
(40 MHz)
HostData0-15
Navigator Motion Processor
HostRdy
~HostSlct
~HostWrite
I/OCP
-55 °C to 150 °C
0 °C to 70 °C*
) 4.75V to 5.25V
cc
HostCmd
~HostRead
20MHz clock
Serial-port
host
Serial port
(alternatives)
Navigator Motion Processor
HostIntrpt
A
B
Encoder
Index
Home
PWM output
Motor amplifier
16-bit data bus
D/A
converter
S
e
AxisIn
AxisOut
A
C
D
o
u
t
p
u
t
P
r
l
a
a
l
i
l
r
p
e
-
o
d
n
w
t
u
o
t
c
g
n
a
r
f
o
u
i
n
t
i
r
p
a
l
i
o
r
Other user devices
External memory
User I/O
Positive
Negative
Hall sensors
(MC2300 only)
Limit
switches
Analog inputs
The CP chip contains the profile generator, which calculates velocity, acceleration, and position
values for a trajectory; and the digital servo filter, which stabilizes the motor output signal. The filter
produces one of two types of output:
• a Pulse-Width Modulated (PWM) signal output which passes via the data bus to the I/O
chip, where the output signal generator sends it to the motor amplifiers; or
MC2800 Technical Specifications
15
• a DAC-compatible value routed via the data bus to the appropriate D/A converter.
Axis position information returns to the motion processor through the I/O chip, in the form of
encoder feedback, or through the CP chip, in the form of parallel-word feedback.
2.5 Peripheral device address mapping
Device addresses on the CP chip’s data bus are memory-mapped to the following locations:
Address Device Description
0200h Serial port data Contains the configuration data (transmission rate,
0800h Parallel-word encoder Base address for parallel-word feedback devices
1000h User-defined Base address for user-defined I/O devices
2000h RAM page pointer Page pointer to external memory
4000h Motor-output DACs Base address for motor-output D/A converters
8000h I/O chip Base address for I/O chip communications
parity, stop bits, etc) for the asynchronous serial port
MC2800 Technical Specifications
16
3 Electrical Characteristics
3.1 DC characteristics
(Vcc and Ta per operating ratings, F
= 40.0 MHz)
clk
Symbol Parameter Minimum Maximum Conditions
Vcc Supply Voltage 4.75 V 5.25 V
Idd Supply Current 120 mA open outputs
Input Voltages
Vih Logic 1 input voltage 2.0 V Vcc + 0.3 V
Vil Logic 0 input voltage -0.3 V 0.8 V
V
Logic 1 voltage for reset pin (reset) 2.2 V Vcc + 0.3 V
ihreset
Output Voltages
Voh Logic 1 Output Voltage 2.4 V @CP Io = -23 mA
@I/O I
= -6 mA
o
Vol Logic 0 Output Voltage 0.33 V @CP Io = 6 mA
= 6 mA
@I/O I
o
Other
I
Tri-State output leakage current
out
Iin Input current
-5 µA 5 µA
-10 µA
-10 µA
Cio Input/Output capacitance 15 pF
10 µA
-10 µA
10 pF
@CP
< Vcc
0 < V
out
@CP
@I/O
0 < V
< Vcc
i
@CP typical
@I/O
Zai Analog input source impedance
E
Differential nonlinearity error.
dnl
Difference between the step width
and the ideal value.
E
Integral nonlinearity error.
inl
Maximum deviation from the best
straight line through the ADC
transfer characteristics, excluding
the quantization error.
3.2 AC characteristics
See timing diagrams, Section 4, for Tn numbers. The symbol “~” indicates active low signal.
Timing Interval Tn Minimum Maximum
Clock Frequency (F
Clock Pulse Width T1 10 nsec
Clock Period (note 3) T2 25 nsec
Encoder Pulse Width T3 150 nsec
Dwell Time Per State T4 75 nsec
) > 0 MHz 40 MHz (note 1)
clk
Analog Input
9kΩ
-1 1.5 LSB
+/-1.5 LSB
MC2800 Technical Specifications
17
Timing Interval Tn Minimum Maximum
Index Setup and Hold (relative to Quad
A and Quad B low)
~HostSlct Hold Time T6 0 nsec
~HostSlct Setup Time T7 0 nsec
HostCmd Setup Time T8 0 nsec
HostCmd Hold Time T9 0 nsec
Read Data Access Time T10 25 nsec
Read Data Hold Time T11 10 nsec
~HostRead High to HI-Z Time T12 20 nsec
HostRdy Delay Time T13 100 nsec 150 nsec
~HostWrite Pulse Width T14 70 nsec
Write Data Delay Time T15 25 nsec
Write Data Hold Time T16 0 nsec
Read Recovery Time (note 2) T17 60 nsec
Write Recovery Time (note 2) T18 60 nsec
Read Pulse Width T19 70 nsec
Address Setup Delay Time T20 7 nsec
Data Access Time T21 19 nsec
Data Hold Time T22 2 nsec
Address Setup Delay Time T23 7 nsec
Address Setup to WriteEnable High T24 72 nsec
RAMSlct Low to WriteEnable High T25 79 nsec
Address Hold Time T26 17 nsec
WriteEnable Pulse Width T27 39 nsec
Data Setup Time T28 3 nsec
Data Setup before Write High Time T29 42 nsec
Address Setup Delay Time T30 7 nsec
Data Access Time T31 71 nsec
Data Hold Time T32 2 nsec
Address Setup Delay Time T33 7 nsec
Address Setup to WriteEnable High T34 122 nsec
PeriphSlct Low to WriteEnable High T35 129 nsec
Address Hold Time T36 17 nsec
WriteEnable Pulse Width T37 89 nsec
Data Setup Time T38 3 nsec
Data Setup before Write High Time T39 92 nsec
Read to Write Delay Time T40 50 nsec
Reset Low Pulse Width T50
RAMSlct Low to Strobe Low T51 1 nsec
Strobe High to RAMSlct High T52 4 nsec
WriteEnable Low to Strobe Low T53 1 nsec
Strobe High to WriteEnable High T54 3 nsec
PeriphSlct Low to Strobe Low T55 1 nsec
Strobe High to PeriphSlct High T56 4 nsec
Device Ready/ Outputs Initialized T57 1 msec
Note 1 Performance figures and timing information valid at F
information and performance parameters at F
T5 0 nsec
5.0 µsec
< 40.0 MHz refer to section 6.1.
clk
= 40.0 MHz only. For timing
clk
Note 2 For 8/8 and 8/16 interface modes only.
Note 3 The clock low/high split has an allowable range of 45-55%.
MC2800 Technical Specifications
18
4 I/O Timing Diagrams
For the values of Tn, please refer to the table in Section 3.2.
4.1 Clock
MasterClkIn
4.2 Quadrature encoder input
T3
Quad A
Quad B
~Index
4.3 Reset
V
cc
T1T2
T3
T4
T5
(= ~QuadA * ~QuadB * ~Index)
T1
T4
T5
Index
I/OClk
~RESET
T50
MC2800 Technical Specifications
19
T57
4.4 Host interface, 8/8 mode
4.4.1 Instruction write, 8/8 mode
T7
~HostSlct
HostCmd
T6
~HostWrite
HostData0-7
HostRdy
4.4.2 Data write, 8/8 mode
~HostSlct
HostCmd
T7
T8
T8
T15
T14
T13
T9
T16
T6
see note
T9
see note
~HostWrite
HostData0-7
HostRdy
T16
T18
T14
T16
Low byte
T15
T13
T14
High byte
T15
Note: If setup and hold times are met, ~HostSlct and HostCmd may be de-asserted at this
point.
MC2800 Technical Specifications
20
4.4.3 Data read, 8/8 mode
~HostSlct
T7
see
note
T6
HostCmd
~HostRead
High-Z
HostData0-7
HostRdy
Note: If setup and hold times are met, ~HostSlct and HostCmd may be de-asserted at this
point.
4.4.4 Status read, 8/8 mode
~HostSlct
T8
T7
T10
T19
High
byte
T11
T12
T17
T6
see
note
High-Z
Low byte
T13
T9
High-Z
HostCmd
~HostRead
HostData0-7
T8
High-Z
T9
T14
T12
T10
T11
MC2800 Technical Specifications
21
High-Z
4.5 Host interface, 8/16 mode
4.5.1 Instruction write, 8/16 mode
T7
~HostSlct
see note
T6
HostCmd
~HostWrite
HostData0-7
HostRdy
Note: If setup and hold times are met, ~HostSlct and HostCmd may be de-asserted at this point.
4.5.2 Data write, 8/16 mode
~HostSlct
T7
T8
T15
T14
T16
T18
T9
see note
T14
T16
Low byteHigh byte
T15
T13
T6
see note
HostCmd
~HostWrite
HostData0-7
HostRdy
T8
see note
T14
High byte
T15
Note: If setup and hold times are met, ~HostSlct and HostCmd may be de-asserted at this
point.
T18
T16
T14
T15
T9
T16
Low byte
T13
MC2800 Technical Specifications
22
4.5.3 Data read, 8/16 mode
~HostSlct
T7
T6
see note
HostCmd
~HostRead
HostData0-7
High-Z
HostRdy
Note: If setup and hold times are met, ~HostSlct and HostCmd may be de-asserted at this
point.
4.5.4 Status read, 8/16 mode
~HostSlct
T8
T7
T10
T19
High
byte
T11
T12
see note
High-Z
Low byte
T13
T9
High-Z
T6
HostCmd
~HostRead
HostData0-7
T8
T17
T19
T12
High-ZHigh-Z
T10
High
byte
T11
MC2800 Technical Specifications
23
Low byte
T9
High-Z
4.6 Host interface, 16/16 mode
4.6.1 Instruction write, 16/16 mode
~HostSlct
HostCmd
T7T6
~HostWrite
HostData0-15
HostRdy
4.6.2 Data write, 16/16 mode
~HostSlct
HostCmd
T8
T14
T15
T13
T7T6
T8
T9
T16
T9
~HostWrite
HostData0-15
HostRdy
T14
T15
T13
MC2800 Technical Specifications
24
T16
4.6.3 Data read, 16/16 mode
~HostSlct
HostCmd
~HostRead
HostData0-15
HostRdy
T7
T8
High-Z
T10
T19
T13
T6
T9
T12
High-Z
T11
4.6.4 Status read, 16/16 mode
~HostSlct
HostCmd
~HostRead
HostData0-15
T7
T8
High-Z
T10
T19
T6
T9
T11
T12
High-Z
MC2800 Technical Specifications
25
4.7 External memory timing
4.7.1 External memory read
Note: PMD recommends using memory with an access time no greater than 15 nsec.
This signal is asserted high to write a host instruction to the Motion
Processor, or to read the status of the HostRdy and HostIntrpt signals. It is
asserted low to read or write a data word.
This signal is used to synchronize communication between the Motion
Processor and the host. HostRdy will go low (indicating host port busy) at
the end of a read or write operation according to the interface mode in
use, as follows:
Interface Mode HostRdy goes low
8/8 after the instruction byte is transferred
after the second byte of each data word is transferred
8/16 after the second byte of the instruction word
after the second byte of each data word is transferred
16/16 after the 16-bit instruction word
after each 16-bit data word
serial n/a
HostRdy will go high, indicating that the host port is ready to transmit,
when the last transmission has been processed. All host port
communications must be made with HostRdy high (ready).
A typical busy-to-ready cycle is 12.5 microseconds.
When ~HostRead is low, a data word is read from the Motion Processor.
When ~HostWrite is low, a data word is written to the Motion Processor.
When ~HostSlct is low, the host port is selected for reading or writing
operations.
I/O chip to CP chip interrupt. This signal sends an interrupt to the CP
chip whenever a host–chipset transmission occurs. It should be
connected to CP chip pin 53, I/OIntrpt.
This signal is high when the I/O chip is reading data from the I/O chip,
and low when it is writing data. It should be connected to CP chip pin 4,
R/W.
This signal goes low when the data and address become valid during
Motion Processor communication with peripheral devices on the data
bus, such as external memory or a DAC. It should be connected to CP
chip pin 6, Strobe.
This signal goes low when a peripheral device on the data bus is being
addressed. It should be connected to CP chip pin 130, PeriphSlct.
These signals are high when the CP chip is communicating with the I/O
chip (as distinguished from any other device on the data bus). They
should be connected to CP chip pins 110 (Addr0), 111 (Addr1), and 128
(Addr15).
This is the master clock signal for the Motion Processor. It is driven at a
nominal 40 MHz
This signal provides the clock pulse for the CP chip. Its frequency is half
that of MasterClkIn (pin 89), or 20 MHz nominal. It is connected directly
to the CP chip I/Oclk signal (pin 58).
MC2800 Technical Specifications
30
Pin Name and
number
HostMode1
HostMode0
91
5
I/O Chip
Direction Description
input These two signals determine the host communications mode, as follows:
These signals transmit data between the host and the Motion Processor
through the parallel port. Transmission is mediated by the control signals
~HostSlct, ~HostWrite, ~HostRead and HostCmd.
In 16 bit mode all 16 bits are used (HostData0-15). In 8 bit mode only the
low-order 8 bits of data are used (HostData0-7). The HostMode0 and
HostMode1 signals select the communication mode this port operates in.
These signals transmit data between the I/O chip and pins Data0-15 of
the CP chip, via the Motion Processor data bus.
MC2800 Technical Specifications
31
Pin Name and
number
PWMMag1A
PWMMag1B
PWMMag1C
PWMSign1A
PWMMag2A
PWMMag2B
PWMMag2C
PWMSign2A
PWMMag3A
PWMMag3B
PWMMag3C
PWMSign3A
21
62
23
61
85
87
86
60
20
19
63
59
I/O Chip
Direction Description
output
output These pins control Axis 2.
output These pins control Axis 3.
These pins provide the Pulse Width Modulated signals for each phase of
the motor. The PWM resolution is 10 bits at a frequency of 20.0 KHz.
These pins control Axis 1.
In 2 or 3-phase PWM 50/50 mode, PWMMag1A/1B/1C are the only
signals and encode both the magnitude and direction in the one signal.
In single-phase PWM sign/magnitude mode, PWMMag1A and
PWMSign1A are the PWM magnitude and direction signals respectively.
In 2-phase PWM sign/magnitude mode, PWMMag1A and PWMSign1A
are the PWM magnitude and direction signals for Phase A. PWMMag1B
and PWMMag1C, “PWMSign1B”, are the PWM magnitude and direction
signals for Phase B.
For MC2840 and MC2820 all pins are valid.
Unused pins may be left unconnected.
Refer to the User’s Guide for more information on PWM encoding
schemes.
In 2 or 3-phase PWM 50/50 mode, PWMMag2A/2B/2C are the only
signals and encode both the magnitude and direction in the one signal.
The PWM resolution is 10 bits at a frequency of 20.0 KHz.
In single-phase PWM sign/magnitude mode, PWMMag2A and
PWMSign2 are the PWM magnitude and direction signals respectively.
In 2-phase PWM sign/magnitude mode, PWMMag2A and PWMSign2A
are the PWM magnitude and direction signals for Phase A. PWMMag2B
and PWMMag2C, “PWMSign2B”, are the PWM magnitude and direction
signals for Phase B.
For MC2840 and MC2820 all pins are valid.
Unused pins may be left unconnected.
In 2 or 3-phase PWM 50/50 mode, PWMMag3A/3B/3C are the only
signals and encode both the magnitude and direction in the one signal.
In single-phase PWM sign/magnitude mode, PWMMag3A and
PWMSign3A are the PWM magnitude and direction signals respectively.
In 2-phase PWM sign/magnitude mode, PWMMag3A and PWMSign3A
are the PWM magnitude and direction signals for Phase A. PWMMag3B
and PWMMag3C, “PWMSign3B”, are the PWM magnitude and direction
signals for Phase B.
For MC2840 all pins are valid. For MC2820 these pins are not valid.
Invalid or unused pins may be left unconnected.
In 2 or 3-phase PWM 50/50 mode, PWMMag4A/4B/4C are the only
signals and encode both the magnitude and direction in the one signal.
In single-phase PWM sign/magnitude mode, PWMMag4A and
PWMSign4A are the PWM magnitude and direction signals respectively.
In 2-phase PWM sign/magnitude mode, PWMMag4A and PWMSign4A
are the PWM magnitude and direction signals for Phase A. PWMMag4B
and PWMMag4C, “PWMSign4B”, are the PWM magnitude and direction
signals for Phase B.
For MC2840 all pins are valid. For MC2820 these pins are not valid.
Invalid or unused pins may be left unconnected.
input
These pins provide the A and B quadrature signals for the incremental
encoder for each axis. When the axis is moving in the positive (forward)
direction, signal A leads signal B by 90°.
The theoretical maximum encoder pulse rate is 5.1 MHz. Actual
maximum rate will vary, depending on signal noise.
NOTE: Many encoders require a pull-up resistor on each signal to
establish a proper high signal. Check your encoder’s electrical
specifications).
For MC2840 all 8 pins are valid. For MC2820 only the first four pins
(axes 1 and 2) are valid.
~Index1
~Index2
~Index3
~Index4
~Home1
~Home2
~Home3
~Home4
49
93
83
28
82
29
88
45
input
input
WARNING! If a valid axis pin is not used, its signal must be
tied high.
Invalid axis pins may be left unconnected.
These pins provide the Index quadrature signals for the incremental
encoders. A valid index pulse is recognized by the chip set when ~Index, A, and B are all low.
For MC2840 all 4 pins are valid. For MC2820 only ~Index1 and ~Index2
are valid.
WARNING! If a valid axis pin is not used, its signal must be
tied high.
Invalid axis pins may be left unconnected.
These pins provide the Home signals, general-purpose inputs to the
position-capture mechanism. A valid Home signal is recognized by the
chipset when ~Homen goes low. These signals are similar to ~Index, but are
not gated by the A and B encoder channels.
For MC2840 all 4 pins are valid. For MC2820 only ~Home1 and ~Home2
are valid.
WARNING! If a valid axis pin is not used, its signal must be
tied high.
Invalid axis pins may be left unconnected.
MC2800 Technical Specifications
33
Pin Name and
Direction Description
number
Vcc 16, 17, 40, 65, 66, 67, 90
GND 4, 9, 22, 34, 46, 57, 64, 72,
84, 96
unassigned 27, 55, 56
All of these pins must be connected to the I/O chip’s digital supply
voltage, which should be in the range 4.75 to 5.25 V.
I/O chip ground. All of these pins must be connected to the digital
power supply return.
These pins must be left unconnected (floating).
5.3.2 Output pin configuration for multiple motor types
The MC2800 chip supports outputting PWM motor commands in both sign/magnitude and 5050
modes. The IO chip supports this operation and assigns pins according to the selected output mode.
The output mode is set using the Navigator command SetOutputMode. This command affects only
the selected axis, so the output for any axis can be selected independently of any other axis.
For axis 1 of the chipset, if the output mode is set to PWM sign/magnitude, the following pinout
should be used.
PWMMag1A
PWMMag1B
PWMSign1A
PWMSign1B
For axis 1 of the chipset, if the output mode is set to PWM 5050, the following pinout should be
used.
PWMMag1A
PWMMag1B
PWMMag1C
For axis 2 of the chipset, if the output mode is set to PWM sign/magnitude, the following pinout
should be used.
PWMMag2A
PWMMag2B
PWMSign2A
PWMSign2B
For axis 2 of the chipset, if the output mode is set to PWM 5050, the following pinout should be
used.
PWMMag2A
PWMMag2B
PWMMag2C
21
62
61
23
21
62
23
85
87
60
86
85
87
86
output
output
output
output
output
output
These pins provide the Pulse Width Modulated signal to the motor. In
PWM 50/50 mode, this is the only signal. In PWM sign-magnitude mode,
this is the magnitude signal.
In PWM sign-magnitude mode, these pins provide the sign (direction) of
the PWM signal to the motor amplifier.
These pins provide the Pulse Width Modulated signals for each phase to
the motor. If the number of phases is 2, only phase A and B are valid. If
the number of phases is 3, phases A,B and C are valid. The number of
phases is set using the Navigator command SetNumberPhases.
In PWM 50/50 mode, these are the only signals.
These pins provide the Pulse Width Modulated signal to the motor. In
PWM 50/50 mode, this is the only signal. In PWM sign-magnitude mode,
this is the magnitude signal.
In PWM sign-magnitude mode, these pins provide the sign (direction) of
the PWM signal to the motor amplifier.
These pins provide the Pulse Width Modulated signals for each phase to
the motor. If the number of phases is 2, only phase A and B are valid. If
the number of phases is 3, phases A,B and C are valid. The number of
phases is set using the Navigator command SetNumberPhases.
In PWM 50/50 mode, these are the only signals.
I/O Chip
MC2800 Technical Specifications
34
For axis 3 of the chipset, if the output mode is set to PWM sign/magnitude, the following pinout
should be used.
PWMMag3A
PWMMag3B
PWMSign3A
PWMSign3B
20
19
59
63
output
output
These pins provide the Pulse Width Modulated signal to the motor. In
PWM 50/50 mode, this is the only signal. In PWM sign-magnitude mode,
this is the magnitude signal.
In PWM sign-magnitude mode, these pins provide the sign (direction) of
the PWM signal to the motor amplifier.
For axis 3 of the chipset, if the output mode is set to PWM 5050, the following pinout should be
used.
PWMMag3A
PWMMag3B
PWMMag3C
20
19
63
output
These pins provide the Pulse Width Modulated signals for each phase to
the motor. If the number of phases is 2, only phase A and B are valid. If
the number of phases is 3, phases A,B and C are valid. The number of
phases is set using the Navigator command SetNumberPhases.
In PWM 50/50 mode, these are the only signals.
For axis 4 of the chipset, if the output mode is set to PWM sign/magnitude, the following pinout
should be used.
PWMMag4A
PWMMag4B
PWMSign4A
PWMSign4B
79
78
26
80
output
output
These pins provide the Pulse Width Modulated signal to the motor. In
PWM 50/50 mode, this is the only signal. In PWM sign-magnitude mode,
this is the magnitude signal.
In PWM sign-magnitude mode, these pins provide the sign (direction) of
the PWM signal to the motor amplifier.
For axis 4 of the chipset, if the output mode is set to PWM 5050, the following pinout should be
used.
PWMMag4A
PWMMag4B
PWMMag4C
79
78
80
output
These pins provide the Pulse Width Modulated signals for each phase to
the motor. If the number of phases is 2, only phase A and B are valid. If
the number of phases is 3, phases A,B and C are valid. The number of
phases is set using the Navigator command SetNumberPhases.
In PWM 50/50 mode, these are the only signals.
Any unused pins may be left unconnected (floating).
MC2800 Technical Specifications
35
5.3.3 CP chip
Pin Name and
number
~WriteEnbl 1
R/~W 4
~Strobe 6
~PeriphSlct 130
~RAMSlct 129
~Reset 41
W/~R 132
SrlRcv 43
CP chip
Direction Description
output When low, this signal enables data to be written to the bus.
output
output
output
output This signal is low indicates when external memory is being accessed.
input
output
input This pin receives serial data from the serial transceiver.
This signal is high when the CP chip is performing a read, and low when it is
performing a write. It should be connected to I/O chip pin 53, CPR/~W.
This signal is low when the data and address are valid during CP
communications. It should be connected to I/O chip pin 54, CPStrobe.
This signal is low when peripheral devices on the data bus are being addressed. It
should be connected to I/O chip pin 52, CPPeriphSlct.
This is the master reset signal. When brought low, this pin resets the chipset to its
initial conditions.
This signal is the inverse of R/~W; it is high when R/~W is low, and vice versa. For
some decode circuits this is more convenient than R/~W.
NOTE! If this signal is not used, it should be tied high.
output This pin transmits serial data to the asynchronous serial port.
output
output When low, this signal causes an interrupt to be sent to the host processor.
input
bi-directional
This pin sets the serial port enable line. SrlEnable is always high for the point-topoint protocol and is high during transmission for the multi-drop protocol.
This signal interrupts the CP chip when a host I/O transfer is complete. It
should be connected to I/O chip pin 77, CPIntrpt.
Multi-purpose data lines. These pins comprise the CP chip’s external data bus,
used for all communications with the I/O chip and peripheral devices such as
external memory or DACs. They may also be used for parallel-word input and
for user-defined I/O operations.
Multi-purpose Address lines. These pins comprise the CP chip’s external address
bus, used to select devices for communication over the data bus. Addr0, Addr1,
and Addr15 are connected to the corresponding CPAddr pins on the I/O chip,
and are used to communicate between the CP and I/O chips.
Other address pins may be used for DAC output, parallel word input, or userdefined I/O operations. See the Navigator Motion Processor User’s Guide for a
complete memory map.
This is the CP chip clock signal. It should be connected to I/O chip pin 24,
CPClk.
CP chip analog power supply voltage. This pin must be connected to the analog
input supply voltage, which must be in the range 4.5-5.5 V
If the analog input circuitry is not used, this pin must be connected to V
CP chip analog high voltage reference for A/D input. The allowed range is
AnalogRefLow to AnalogVcc.
If the analog input circuitry is not used, this pin must be connected to V
CP chip analog low voltage reference for A/D input. The allowed range is
AnalogGND to AnalogRefHigh.
If the analog input circuitry is not used, this pin must be connected to GND.
CP chip analog input ground. This pin must be connected to the analog input
power supply return.
If the analog input circuitry is not used, this pin must be connected to GND.
These signals provide general-purpose analog voltage levels, which are sampled
by an internal A/D converter. The A/D resolution is 10 bits.
The allowed range is AnalogRefLow to AnalogRefHigh.
Any unused pins should be tied to AnalogGND.
If the analog input circuitry is not used, these pins should be tied to GND.
These signals provide inputs from the positive-side (forward) travel limit
switches. On power-up or Reset these signals default to active low interpretation,
but the interpretation can be set explicitly using the
SetSignalSense instruction.
For MC2840 all 4 pins are valid. For MC2820 only PosLim1 and PosLim2 are
valid.
.
cc
.
cc
WARNING! If a valid axis pin is not used, its signal must be tied
high. PosLim2 is an output during device reset and as such any
connection to GND or V
Invalid axis pins may also be left unconnected.
MC2800 Technical Specifications
37
must be via a series resistor.
cc
Pin Name and
number
PosLim3/
Synch
54
CP chip
Direction Description
input/output
On the MC2840 chipset, this pin is the positive-side (forward) travel limit switch
for axis#3. On the MC2820 chipset this pin is not used.
On the MC28x3 chipset, this pin is the synchronization signal. In the disabled
mode, the pin is configured as an input and is not used. In the master mode, the
pin outputs a synchronization pulse that can be used by slave nodes or other
devices to synchronize with the internal chip cycle of the master node. In the
slave mode, the pin is configured as an input and a pulse on the pin synchronizes
the internal chip cycle.
WARNING! If a valid axis limit pin is not used, its signal should
be tied high.
input On the MC28x0 chipset, this pin is not used.
On the MC2843 chipset, this pin is the positive-side (forward) travel limit switch
for axis#3. On the MC2823 chipset this pin is not used.
WARNING! If a valid axis limit pin is not used, its signal should
be tied high.
input
These signals provide inputs from the negative-side (reverse) travel limit
switches. On power-up or Reset these signals default to active low interpretation,
but the interpretation can be set explicitly using the
For MC2840 all 4 pins are valid. For MC2820 only NegLim1 and NegLim2 are
valid.
WARNING! If a valid axis pin is not used, its signal must be tied
high. NegLim1 is an output during device reset and as such any
output
input
input
connection to GND or V
Invalid axis pins may also be left unconnected.
Each of these pins can be conditioned to track the state of any bit in the Status
registers associated with its axis.
For MC2840 all 4 pins are valid. For MC2820 only AxisOut1 and AxisOut2 are
valid.
Invalid or unused pins may be left unconnected.
These are general-purpose programmable inputs. They may be used as a
breakpoint input, to stop a motion axis, or to cause an UPDATE to occur.
For MC2840 all 4 pins are valid. For MC2820 only AxisIn1 and AxisIn2 are valid.
Invalid or unused pins may be left unconnected.
Hall sensor inputs. Each set (A, B, and C) of signals encodes 6 valid states as
follows: A on, A and B on, B on, B and C on, C on, C and A on. A sensor is
defined as being on when its signal is high.
Note: These signals should only be connected to Hall sensors that are mounted
at a 120° offset. Schemes which provide Hall signals 60° apart will not work.
For MC2840 all 12 pins are valid. For MC2820 only the first six pins (axes 1 and
2) are valid. Invalid or unused pins may be left unconnected.
CP digital supply voltage. All of these pins must be connected to the supply
voltage. V
WARNING! Pin 35 must be tied HIGH with a pull-up resistor. A
nominal value of 22K Ohms is suggested.
must be in the range 4.75 - 5.25 V.
cc
GND
AGND
unassigned
unassigned
3, 8, 14, 20, 29, 37, 46,
CP ground. All of these pins must be connected to the power supply return.
56, 59, 61, 71, 92, 104,
113, 120
78-81 These signals must be tied to AnalogGND.
If the analog input circuitry is not used, these pins must be tied to GND.
48
These signals may be connected to GND for better noise immunity and reduced
power consumption or they can be left unconnected (floating).
5, 30-34, 38, 39, 42,
These signals must be left unconnected (floating).
57, 131
MC2800 Technical Specifications
39
6 Application Notes
6.1 Design Tips
The following are recommendations for the design of circuits that utilize a PMD Motion Processor.
Serial Interface
The serial interface is a convenient interface that can be used before host software has been written
to communicate through the parallel interface. It is recommended that even if the serial interface is
not utilized as a standard communication interface, that the serial receive and transmit signals are
brought to test points so that they may be connected during initial board configuration/debugging.
This is especially important during the prototype phase. The serial receive line should include a pullup resistor to avoid spurious interrupts when it is not connected to a transceiver.
If the serial configuration decode logic is not implemented (see section 6.3) and the serial interface
may be used for debugging as mentioned above, the CP data bus should be tied high. This places the
serial interface in a default configuration of 9600,n,8,1 after power on or reset.
Controlling PWM output during reset
When the motion processor is in a reset state (when the reset line is held low) or immediately after a
power on, the PWM outputs can be in an unknown state, causing undesirable motor movement. It is
recommended that the enable line of any motor amplifier be held in a disabled state by the host
processor or some logic circuitry until communication to the motion processor is established. This
can be in the form of a delay circuit on the amplifier enable line after power up, or the enable line can
be ANDed with the CP reset line.
Parallel word encoder input
When using parallel word input for motor position, it is useful to also decode this information into
the User I/O space. This allows the current input value to be read using the chip instruction ReadIO
for diagnostic purposes.
Using a non standard system clock frequency
It is often desirable to share a common clock among several components in a design. In the case of
the PMD Motion Processors it is possible to use a clock below the standard value of 40MHz. In this
case all system frequencies will be reduced as a fraction of the input clock verses the standard
40MHz clock. The list below shows the affected system parameters:-
• Serial baud rate
• PWM carrier frequency
• Timing characteristics as shown in section 3.2
• Cycle time
• Commutation rate
MC2800 Technical Specifications
40
For example, if an input clock of 34MHz is used with a serial baud rate of 9600 the following timing
changes will result:-
• Serial baud rate decreases to 9600 bps *34/40 = 8160 bps
• PWM frequency decreases to 20 KHz *34/40 = 17 KHz
• Cycle time per axis increases to 153.6 µsec *40/34 = 180.71 µsec
• Commutation rate for MC2820 decreases to 20KHz *34/40 = 17 KHz
• Commutation rate for MC2840 decreases to 10KHz *34/40 = 8.5 KHz
MC2800 Technical Specifications
41
6.2 ISA Bus Interface
A complete, ready-to-use ISA (PC/AT) bus interface circuit has been provided to illustrate Navigator
host interfacing, as well as to make it easier for the customer to build a Navigator development
system.
The interface between the PMD Navigator chipset and the ISA (PC-AT) bus is shown on the
following page.
Comments on Schematic
This interface uses a CPLD and two 74LS245s to buffer the data lines. This interface assumes a base
address is assigned in the address space of A9-A0, 300-400 hex. These addresses are generally
available for prototyping and other system-specific uses without interfering with system assignments.
This interface occupies 16 addresses from XX0 to XXF hex though it does not use all the addresses.
Four select lines are provided allowing the base address to be set from 300 to 3F0 hex for the select
lines SW1-SW4 equal to 0- F respectively. The address assignments used are as follows, where
BADR is the base address, 340 hex for example:
Address use
340h read-write data
342h write command -read status
344h write command -read status
348h write reset [Data = don't care]
The base address (BADR) is decoded in the 74LS688. It is combined with SA1, SA2, and SA3,
(BADR+0,2,4) to form HSELN to select the I/O chip and the 245’s. (BADR+2,4) asserts HCMD.
Two addresses are used to be compatible with the first generation products, which used BADR+2 to
write command and BADR+4 to read status.
B+8 and IOW* generate a reset pulse, -RS, for the CP chip. The reset instruction is OR'd with
RESET on the bus to initialize the PMD chipset when the PC is reset.
MC2800 Technical Specifications
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MC2800 Technical Specifications
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6.3 RS-232 Serial Interface
The interface between the Navigator chipset and an RS-232 serial port is shown in the following
figure.
Comments on Schematic
S1 and S2 encode the characteristics of the serial port such as baud rate, number of stop bits, parity,
etc. The CP will read these switches during initialization, but these parameters may also be set or
changed using the
connected directly to the serial port of a PC without requiring a null modem cable.
SetSerialPort chipset command. The DB9 connector wired as shown can be
MC2800 Technical Specifications
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MC2800 Technical Specifications
45
6.4 RS 422/485 Serial Interface
The interface between the Navigator chipset and an RS-422/485 serial port is shown in the following
figure.
Comments on Schematic
Use the included table to determine the jumper setup that matches the chosen configuration. If
using RS485, the last CP must have its jumpers set to RS485 LAST. The DB9 connector wiring is
for example only. The DB9 should be wired according to the specification that accompanies the
connector to which it is attached.
For correct operation, logic should be provided that contains the start up serial configuration for the
chipset. Refer to the RS232 Serial Interface schematic for an example of the required logic.
Note that the RS485 interface cannot be used in point to point mode. It can only be used in a multidrop configuration where the chip SrlEnable line is used to control transmit/receive operation of the
serial transceiver.
Chips in a multi-drop environment should not be operated at different baud rates. This will result in
communication problems.
MC2800 Technical Specifications
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MC2800 Technical Specifications
47
6.5 3 Phase PWM Motor Interface
The following schematic shows a typical interface circuit between the MC2840 and an amplifier used
in PWM 50/50 output mode.
Comments on Schematic
The L6234 from ST MicroElectronics is an integrated package that provides 3 half-bridge amplifiers
on a single chip. It can drive up to 2 Amps continuous at 52 Volts.
MC2800 Technical Specifications
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MC2800 Technical Specifications
49
6.6 Single Phase PWM Motor Interface
The following schematic shows a typical interface circuit between the MC2840 and an amplifier in
PWM Sign/Magnitude output mode.
Comments on Schematic
The LMD18200 H-bridge driver is used. To simplify the schematic, a diode bridge has been shown
for 1 axis only. The diode bridge for the other 3 axes is identical.
MC2800 Technical Specifications
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MC2800 Technical Specifications
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6.7 12-bit Parallel DAC Interface
The interface between the MC2840 chip set and 2 quad 12 bit DAC’S is shown in the following
figure.
Comments on Schematic
The 12 data bits are written to the DAC addressed by address bits A0 and A1 in Quad DAC 1, when
A2 is 0. The 12 data bits are written to the DAC addressed by address bits A0 and A1 in quad DAC
2, when A2 is 1. In this fashion CP addresses 4000,4002,4004,and 4006 are used for axis 1-4, phase
A, and 4001,4003, 4005, and 4007, are used for axis 1-4 phase B.
MC2800 Technical Specifications
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MC2800 Technical Specifications
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6.8 16-bit Serial DAC Interface
The following schematic shows an interface circuit between the MC2840 and a dual 16-bit serial
DAC.
Comments on Schematic
The 16 data bits from the CP chip are latched in the two 74H165 shift registers when the CP writes
to address 400x hex, and the address bits A1 and A2 are latched in the 2 DLAT latches and decoded
by the 138 CPU cycle. The fed-back and-or gate latches, the decoded WRF, and the next clock will
clear the 1
the second DFF3 flop, forcing DACWRN low, and setting the first flop since WRF will have gone
high. DACWRN low will clear the 74109, SHFTCNTN. The 4 bit counter, 74161, is also parallel
loaded to 0, and the counter is enabled by ENP going high. The counter will not start counting nor
the shift register start shifting until the clock after the DACWRN flop sets since the load overrides
the count enable. When the DACWR flop is set the shift register will start shifting and the counter
will count the shifts. After 15 shifts CNT15 from the counter will go high and the next clock will set
the DACLAT flop and set the SHFTCNTN flop. This will stop the shift after 16 shifts and assert
L1 through L4 depending on the address stored in the latch. The 16th clock also was counted
causing the counter to roll over to 0 and CNT15 to go low. The next clock will therefore clear the
DACLAT flop causing the DAC latch signal L1 through L4 to terminate and the 16 bits of data to be
latched in the addressed DAC. The control logic is now back in its original state waiting for the next
write to the DACs by the CP. SERCK is a 10MHz clock, the 20MHz CP clock divided by 2, since
the AD1866 DACs will not run at 20MHz.
st
sequencer flop DFF3. This will disable the WRF latch and the second clock will clear
MC2800 Technical Specifications
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MC2800 Technical Specifications
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6.9 12-bit A/D Interface
The following schematic shows a typical interface circuit between the Navigator chipset and a quad
12 bit 2’s complement A/D converter used as a position input device.
Comments on Schematic
The A/D converter samples all 4 axes and sequentially converts and stores the 2’s complement
digital words. The data is read out sequentially, axis 1 to 4. DACRD- is used to perform the read
and is also used to load the counter to FFh. The counter will be reloaded for each read and will not
count significantly between reads. The counter will therefore start counting down after the last read
and will generate the cvt- pulse after 12.75 µsec. The conversions will take approximately 35 µsec,
and the data will be available for the next set of reads after 50 µsec. The 12 bit words from the A/D
are extended to 16 bits with the 74LS244.
MC2800 Technical Specifications
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MC2800 Technical Specifications
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6.10 16-bit A/D Input
The interface between the Navigator chipset and 16 bit A/D converters as parallel input position
devices is shown in the following figure.
Comments on Schematic
The schematic shows a 16 bit A/D used to provide parallel position input to axis 1 and axis 2. The
expansion to the remaining two axes is easily implemented. The 374 registers are required on the
output of the A/D converters to make the 68-nanosecond access time of the CP. The worst-case
timing of the A/D’s specify 83 nanoseconds for data on the bus and 83 nanoseconds from data to
tri-state on the bus. Each time the data is read the 169 counter is set to 703 decimal. This provides a
35.2-microsecond delay before the next conversion. With a 10-microsecond conversion time the
data will be available for the next set of reads after 50 microseconds. The delay is used to provide a
position sample close to the actual position.
MC2800 Technical Specifications
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MC2800 Technical Specifications
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6.11 RAM Interface
The following schematic shows an interface circuit between the Navigator chipset and external ram.
Comments on Schematic
The CP is capable of directly addressing 32K words of 16-bit memory. It will also use a 16 bit
paging register to address up to 32K word pages. The schematic shows the paging and addressing
for 128KB RAM chips, i.e. 4 pages per RAM chip. The page address decoding is shown for only 6 of
the 16 possible paging bits. The decoding time from W/R and DS- to the memory output must not
exceed 18 ns. for a read with no wait states. The writes provide 25 extra ns access time for W/R and
DS- to reverse the CP data bus.
MC2800 Technical Specifications
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MC2800 Technical Specifications
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6.12 User-defined I/O
The interface between the Navigator chipset and 16 bits of user output and 16 bits of user input is
shown in the following figure.
Comments on Schematic
The schematic implements 1 word of user output registered in the 74LS377’s and 1 word of user
inputs read via the 244’s. The schematic decodes the low 3 bits of the address to 8 possible UIO
addresses UIO0 through UIO7. Registers and buffers are shown for only UIO0, but the
implementation shown may be easily extended. The lower 8 address bits may be decoded to provide
up to 256 user output words and 256 user input words of 16 bits.
MC2800 Technical Specifications
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MC2800 Technical Specifications
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