CMLMICRO MX809J

DATA BULLETIN
MX809
1200bps MSK Modem
PRELIMINARY INFORMATION
Features
Half-Duplex 1200bps MSK Modem
operating under C-BUS control
Software Selectable Checksum
Generation and Error Checking in
accordance with MPT1327
RECOVERED
CLOCK
Low Power Operation
Member of DBS800 Family (C-BUS
Compatible)
CHECKSUM
GEN/CHECK
VDD
BYTE COUNTER
RX IN
MSK
RECEIVER
DATA REGISTER 1
SYNC/SYNC
DETECT
ä
ä
RX SYNC
DETECT
CLOCK
GENERATOR
VBIAS
RX SYNC
DETECT
AMP IN
ä
RX FREEFORMAT
TX OUT
ä
XTAL/
CLOCK
XTAL
MSK
TRANSMITTER
DATA REGISTER 2
RECOVERED
CLOCK
RX DATA BUFFER
TX DATA BUFFER
_
ä
CS
RX DATA
READY
REPLY
DATA
SYNC PROGRAM
LOW - HIGH
8-BIT PARALLEL BUS
VBIAS
AMP OUT
V SS
ä
WAKE
RX SYNC
DETECT
RX SYNC
DETECT
ä
CONTROL
LOGIC
ä
COMMAND
DATA
ä
AND
+
UNCOMMITTED
AMPLIFIER
ä
SERIAL
CLOCK
INTERRUPT
ENABLE
TX IDLE
ä
C-BUS
INTERFACE
TX DATA
READY
ADDRESS
DECODER
CONTROL
REGISTER
STATUS
REGISTER
INTERRUPT
GENERATOR
IRQ
ADDRESS
SELECT
The MX809 is an intelligent, half-duplex 1200-baud MSK Modem, which operates under C-BUS control. This
modem provides software selectable checksum generation and error checking in accordance with MPT1327.
In TX Mode the MX809 will:
1.
a) Accept from the host and transmit 8-bit bytes of data as instructed (preamble, sync, address, and data), or
b) Internally calculate and inset a 2 byte checksum based on the preceding 6 bytes f data, or
c) Disable the internal checksum generator and continuously transmit the data supplied.
2.
Transmit 1 hang-bit and go to TX idle when all loaded data bytes have been transmitted.
In RX Mode the MX809 will:
1.
2.
Detect and carry out bit synchronization within 16 bits.
a) Search and detect the user-programmed Sync (or its opposite logic sense) Word and carry out frame
synchronization. Data will then be output in 8-bit bytes via the RX Data Buffer.
b) Use the received checksum to calculate the presence of any errors, setting the Status Register accordingly.
3.
Make the incoming data directly available via the RX Data Buffer (RX Freeformat), overriding the synchronization
requirements.
RX input timing is achieved by recovering an RX clock from the incoming data stream. Output tones are
timed to the internally generated TX clock. Filter, register clocks, and transmit MSK tone frequencies are
derived internally from the external Xtal or clock pulse input.
A 4.032MHz Xtal or clock input is required for compliance with the MPT1327 Signaling Specification. Note:
All information contained in this data bulletin is specified using a 4.032MHz Xtal, 1200bps baud rate, with
Mark and Space frequencies of 1200Hz and 1800Hz. The MX809 has a non-committed amplifier on-chip for
general applications in the DBS 800 series.
The MX809 may be used with a 5.0V power supply and is available in the following packages:
24-pin PLCC (MX809LH), and 24-pin CERDIP (MX809J).
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
2
MX809
Contents
Section
Page
1 Block Diagram................................................................................................................ 3
2 Signal List....................................................................................................................... 4
3 External Components.................................................................................................... 6
4 General Description....................................................................................................... 7
5 Controlling Protocol ...................................................................................................... 7
5.1
5.2
5.3
5.4
5.5
5.6
5.7
5.8
5.9
Address/Commands ............................................................................................................ 7
Address Select .................................................................................................................... 8
Write to Control Register ..................................................................................................... 9
RX Data buffer -- “Read RX Data Buffer” ............................................................................ 9
TX Data Buffer -- “Write to TX Data Buffer” ....................................................................... 10
SYNC Program -- “Write to SYNC Program” ..................................................................... 10
Read Status Register ........................................................................................................ 10
Interrupt Request............................................................................................................... 11
General Reset ................................................................................................................... 11
6 Application ................................................................................................................... 12
6.1
6.2
6.3
6.4
6.5
Checksum Generation and Checking ................................................................................ 12
6.1.1
Generation .............................................................................................................................. 12
6.1.2
Checking ................................................................................................................................. 12
Modem Performance ......................................................................................................... 12
Modem Timing Information................................................................................................ 13
TX Timing .......................................................................................................................... 14
6.4.1
TX More Than One Message, SYNC Before Every Message, TX Checksum Enabled ......... 14
6.4.2
TX More Than One Message, TX Checksum Not Enabled. ................................................... 14
6.4.3
TX One Message, TX Checksum Enabled ............................................................................. 15
6.4.4
TX One Message, TX Checksum Not Enabled....................................................................... 15
RX Timing.......................................................................................................................... 16
6.5.1
RX SYNC / SYNC Required Before Every Message, Rx Checksum Not Enabled ................. 16
6.5.2
RX Additional Data Follows Initial Address (6 Data & 2 Checksum Bytes) Data, RX checksum
Enabled................................................................................................................................... 16
7 Performance Specifications........................................................................................ 17
7.1
7.2
Electrical Specifications..................................................................................................... 17
7.1.1
Absolute Maximum Limits ....................................................................................................... 17
7.1.2
Operating Limits...................................................................................................................... 17
7.1.3
Operating Characteristics ....................................................................................................... 18
7.1.4
Timing ..................................................................................................................................... 20
Packages........................................................................................................................... 21
MXCOM, Inc. reserves the right to change specifications at any time without notice.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
3
MX809
1 Block Diagram
RECOVERED
CLOCK
CHECKSUM
GEN/CHECK
VDD
BYTE COUNTER
RX IN
MSK
RECEIVER
DATA REGISTER 1
XTAL/
CLOCK
SYNC/SYNC
DETECT
ä
CLOCK
GENERATOR
ä
RX SYNC
DETECT
VBIAS
RX SYNC
DETECT
AMP IN
ä
RX FREEFORMAT
TX OUT
ä
RECOVERED
CLOCK
XTAL
MSK
TRANSMITTER
DATA REGISTER 2
RX DATA BUFFER
TX DATA BUFFER
_
ä
CS
REPLY
DATA
INTERRUPT
ENABLE
VBIAS
ä
AMP OUT
V SS
ä
WAKE
RX SYNC
DETECT
RX SYNC
DETECT
ä
CONTROL
LOGIC
+
UNCOMMITTED
AMPLIFIER
ä
8-BIT PARALLEL BUS
AND
TX IDLE
SYNC PROGRAM
LOW - HIGH
ä
COMMAND
DATA
C-BUS
INTERFACE
TX DATA
READY
ä
SERIAL
CLOCK
RX DATA
READY
ADDRESS
DECODER
CONTROL
REGISTER
STATUS
REGISTER
INTERRUPT
GENERATOR
IRQ
ADDRESS
SELECT
Figure 1: Block Diagram
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
4
MX809
2 Signal List
Pin
1
Signal
Xtal
Description
This is the output of the on-chip clock oscillator. External components are
required at this output when a Xtal is used. See Figure 2. Inset
2
Xtal/Clock
3
IRQ
4
5
N/C
N/C
6
RX Freeformat
When this input is logic “0” in the RX Mode, it allows received data to be read
from the RX Data Buffer via the Reply Data line without having to achieve byte
synchronization (SYNC/ SYNC ) first. Data will continue to be available after this
input goes to a logic “1” until either a SYNC or SYNC Prime Bit is set or the
modem is set to TX Mode. When held at a logic “1” the modem operates
normally. This pin has an internal 1M pull-up resistor.
Note: If this input is held at a logic “0” in the TX Mode, the RX Data Ready bit in
the Status Register may occasionally be set, but not cause an interrupt. If this
input is a logic “0” when going into the RX Mode, and RX Data Ready interrupt
may be generated immediately (in this case the first byte of RX data should be
ignored).
7
VBIAS
The internal circuitry bias line, this is held at VDD/2. This pin must be decoupled
to VSS by capacitor C3. See Figure 2.
8
9
10
Amp In
Amp Out
RX In
The inverting input to the on-chip uncommitted amplifier.
The output of the on-chip uncommitted amplifier.
This is the 1200 baud, 1200Hz/1800Hz received MSK signal input. The input
signal to this pin must be AC coupled via capacitor C4. See Figure 2.
11
12
N/C
VSS
13
TX Out
14
15
16
17
N/C
N/C
N/C
Reply Data
18
19
N/C
CS
Chip Select . This is the ‘C-BUS’ data loading control function. This input is
provided by the microcontroller. Data transfer sequences are initiated, completed
or aborted by the CS signal. See Section 6 and Section 7.1.4.
20
Command Data
This is the ‘C-BUS’ serial data input from the microcontroller. Data is loaded to
this device in 8-bit bytes, MSB (bit 7) first and LSB (bit 0) last, synchronized to the
Serial Clock. See Section 6 and Section 7.1.4.
1998 MX-COM, Inc.
This is the input to the on-chip clock oscillator inverter. A Xtal or externally
derived clock should be connected here. See Figure 2. Inset
The output of this pin indicates an interrupt condition to the microcontroller by
going to a logic “0”. This is a “wire-or-able” output that enables the connection of
up to 8 peripherals to 1 interrupt port on the microcontroller. This pin is an opendrain output, and therefore has a low impedance pulldown to logic “0” when active
and a high impedance when inactive. The conditions that cause interrupts are
indicted in the Status Register and are shown in Table 2. The system IRQ line
requires a pull-up resistor to VDD.
Negative Supply (GND)
This is the 1200 baud, 1200Hz/1800Hz MSK TX output. When not transmitting
data the output impedance of this pin is high. On power-up this output can be any
level. A General Reset command is required to ensure that this output attains
VBIAS initially.
This is the C-BUS serial data output to the microcontroller. The transmission of
Reply Data bytes is synchronized to the Serial Clock under the CS input. This 3state output is held high impedance when not sending data to the microcontroller.
See Section 6 and Section 7.1.4.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
5
MX809
Pin
21
Signal
Serial Clock
Description
This is the ‘C-BUS’ serial Clock input. This clock, produced by the
microcontroller, is used for transfer timing of commands and data to and from the
MSK Modem. See Section 6 and Section 7.1.4.
This pin enables two MX809s to be used on the same C-BUS, providing fullduplex operation. When at a logic “1” Address/Command bytes (with the
exception of a General Reset) must have bit 3 set to a logic “1” to address this
device. See Table 5 and Table 6.
22
Address Select
23
Wake
This input can be used to reactivate the MX809 from Powersave. The device will
be in Powersave when both this pin and bit 2 of the Control Register are set to
logic “1”. Recovery from Powersave is achieved by putting either the Wake pin or
the Powersave bit in the Control Register to logic “0”. This allows MX809
activation by the microcontroller or an external signal, such as R.S.S.I. or Carrier
Detect. See Table 3.
24
VDD
Positive supply. A single +5.0V power supply is required. Levels and voltages
within the MSK Modem are dependent upon this supply.
Table 1: Signal List
TX Idle
RX Data Ready
RX SYNC Detect
TX Data Ready
RX Sync Detect
Interrupt outputs can be disabled by bit 3 of the Control Register
Table 2: IRQ Conditions
Powersave (CR bit 2)
Wake
MX809 Condition
1
0
1
0
1
1
0
0
Powersave
Enabled
Enabled
Enabled
Table 3:
1998 MX-COM, Inc.
Wake and Powersave Conditions
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
6
MX809
3 External Components
XTAL
➤
R2
SEE INSET XTAL/CLOCK
➤
IRQ
➤
RX FREEFORMAT
➤
VBIAS
AMP IN ➤
C3
AMP OUT
➤
RX IN
➤
C4
VSS
➤
1
2
3
4
5
6
7
8
9
10
11
12
V
MX809J
24 ➤ DD
WAKE
23 ➤
➤
22 ADDRESS SELECT
21 ➤SERIAL CLOCK
COMMAND DATA
20 ➤
CS
19 ➤
18
➤
17 REPLY DATA
16
15
14
TX OUT
➤
13
C5
INSET
XTAL
1
X1
MX809J
R1
2
XTAL/CLOCK
C2
C1
Figure 2: Recommended External Components
Component
R1
Notes
1.0M
Tolerance
±10%
22.0K
±10%
33pF
33pF
±20%
±20%
C3
1.0F
±20%
C4
0.1F
±20%
C5
1.0F
±20%
R2
C1
C2
X1
1
1
1
Value
4.032MHz
Table 4: Recommended External Components
Recommended External Component Notes:
1. Xtal circuit capacitors C1 (CD) and C2 (CG) shown in Inset 2 are recommended in accordance with MXCOM’s Crystal Oscillator Application Note.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
7
MX809
4 General Description
The MX809 is an intelligent, half-duplex 1200-baud MSK Modem, which operates under C-BUS control. This
modem provides software selectable checksum generation and error checking in accordance with MPT1327.
In TX Mode the MX809 will:
1.
a) Accept from the host and transmit 8-bit bytes of data as instructed (preamble, sync, address, and data), or
b) Internally calculate and inset a 2 byte checksum based on the preceding 6 bytes of data, or
c) Disable the internal checksum generator and continuously transmit the data supplied.
2.
Transmit 1 hang-bit and go to TX idle when all loaded data bytes have been transmitted.
In RX Mode the MX809 will:
1.
Detect and carry out bit synchronization within 16 bits.
2.
a) Search and detect the user-programmed Sync (or its opposite logic sense) Word and carry out frame
synchronization. Data will then be output in 8-bit bytes via the RX Data Buffer.
b) Use the received checksum to calculate the presence of any errors, setting the Status Register accordingly.
3.
Make the incoming data directly available via the RX Data Buffer (RX Freeformat), overriding the synchronization
requirements.
RX input timing is achieved by recovering an RX clock from the incoming data stream. Output tones are
timed to the internally generated TX clock. Filter, register clocks, and transmit MSK tone frequencies are
derived internally from the external Xtal or clock pulse input.
A 4.032MHz Xtal or clock input is required for compliance with the MPT1327 Signaling Specification. Note:
All information contained in this data bulletin is specified using a 4.032MHz Xtal, 1200bps baud rate, with
Mark and Space frequencies of 1200Hz and 1800Hz. The MX809 has a non-committed amplifier on-chip for
general applications in the DBS 800 series.
5 Controlling Protocol
Control of the functions within the MX809 MSK Modem is by a group of Address/Commands and appended
data instructions from the system microcontroller. Two separate MSK Modems can be addressed. The use
of these A/Cs is detailed in the following paragraphs and tables.
Command Assignment
Address/Command
Binary
HEX
MSB
Command Data
LSB
General Reset
01
00000001
Control Register bits set to logic “0”
Write to Control Register
40
01000000
+
1 byte instruction to Control Register
Read Status Register
41
01000001
+
1 byte reply from Status Register
Read RX Data Buffer
42
01000010
+
1 byte of data from RX Data Buffer
Write to TX Data Buffer
43
01000011
+
1 byte of data to TX Data Buffer
Write to SYNC Program
44
01000100
+
2 bytes of SYNC Word to SYNC
Program. Register
Table 5: Modem No. 1 C-BUS Address/Commands – (Address Select input at a logic “0”)
5.1
Address/Commands
Instructions and data transactions to and from the MX809 consist of an Address/Command (A/C) byte
followed by either further instructions or data, or a Status or RX Data Reply.
Control and configuration is by writing instructions from the microcontroller to the Control Register [40H (48H)].
Reporting of the MX809 configuration is by reading the Status Register [41H (49H)]. Instructions and data are
transferred via C-BUS in accordance with the timing information given in Figure 11.
Data to be transmitted as MSK is sent to the TX Data Buffer via the Command Data line. Received data is
read from the RX Data buffer via the Reply Data line.
Instructions and data transactions to and from this device are preceded by the relevant A/C.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
8
MX809
C-BUS allocations for the MX809 are shown in Table 5 and Table 6.
Command Assignment
Address/Command
Binary
HEX
MSB
Command Data
LSB
General Reset
01
00000001
Control Register bits set to logic “0”
Write to Control Register
48
01001000
+
1 byte instruction to Control Register
Read Status Register
49
01001001
+
1 byte reply from Status Register
Read RX Data Buffer
4A
01001010
+
1 byte of data from RX Data Buffer
Write to TX Data Buffer
4B
01001011
+
1 byte of data to TX Data Buffer
Write to SYNC Program
4C
01001100
+
2 bytes of SYNC Word to SYNC
Program Register
Table 6: Modem No. 2 C-BUS Address/Commands – (Address Select input at a logic “1”)
5.2
Address Select
This input allows 2 MSK Modems on the same BUS, using the correct addressing.
When operating in a system using 2 MSK Modems, one MSK Modem is designated No. 1 and requires its
Address Select input to be held at a logic “0”. The second Modem (No. 2) requires its Address select input to
be held at logic “1”.
All C-BUS transactions with Modem 1 will use Address/Command allocations 40H to 44H (Table 5) and
transactions with Modem 2 will use 48H to 4CH (Table 6).
For explanation purposes, further descriptions of MX809 MSK Modem internal register functions will deal
primarily with MSK Modem No. 1 (Address Select at logic “0”).
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
5.3
9
MX809
Write to Control Register
This “Write Only” register directs the Modem’s operation.
SYNC : When set, this bit enables SYNC Word detection. It is cleared on a successful SYNC Word
detection.
SYNC Prime: When set, this bit enables SYNC Word detection. It is cleared on a successful SYNC Word
detection.
Interrupt Enable: When set, this bit allows interrupts to be output by the MX809 on the IRQ line.
Powersave: Used in conjunction with the Wake input (see Section 2) to control the Powersave state of the
MX809.
Checksum Enable: When set:
In TX: A 2-byte checksum is generated and transmitted after every 6 bytes transmitted.
In RX: After every 8 received bytes (6 information + 2 checksum) the checksum word is checked. If
the checksum is correct, the RX Checksum True bit in the Status Register is set to a logic “1”. When
this bit is a logic “0” no checksum are generated or checked.
Note: Checksum operation is inhibited during the SYNC / SYNC search period.
Setting
MSB
Bit 7
6
5
Control bits
Transmitter first
Not Used
Set to “0”
Not Used
Set to “0”
SYNC Prime
0
1
4
0
1
3
0
1
2
0
1
1
0
1
0
0
1
Primed
SYNC Prime
Primed
Interrupt Enable
Disable
Enable
Powersave
Normal Operation
Powersave
Checksum Enable
Disable
Enable
RX/TX Mode
RX
TX
Table 7: Control Register
5.4
RX Data buffer -- “Read RX Data Buffer”
This “Read Only” register contains the last byte of data received from the Data Register. Data is received Bit
7 (MSB) first.
MSB
7
1998 MX-COM, Inc.
LSB
6
5
4
3
2
RX Data Buffer
1
0
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4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
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MSK Modem
5.5
10
MX809
TX Data Buffer -- “Write to TX Data Buffer”
This “Write Only” register contains the next byte of data to be transmitted. Bit 7 (MSB) is transmitted first.
MSB
7
5.6
LSB
6
5
4
3
2
TX Data Buffer
1
0
SYNC Program -- “Write to SYNC Program”
This “Write Only” register is loaded with the required SYNC word. This word (or its opposite logic sense,
SYNC ) is compared with the received synchronization word. If the required SYNC Word is less that 16bits,
the remaining bits must be programmed as preamble (10101010…etc). Bit 15 (MSB) is loaded first.
MSB
15
5.7
14
13
Byte 1
12
11
10
SYNC High
9
8
7
6
5
Byte 2
4
3
SYNC Low
LSB
2
1
0
Read Status Register
This “Read Only” register indicated the source of MX809 interrupts ( IRQs ).
RX SYNC Detect: This is set and an Interrupt is generated when the correct SYNC Word is detected (if
SYNC Prime is set).
It is cleared by (1) reading the Status Register, and (2) setting RX / TX to logic “1”.
RX SYNC Detect: This is set and an Interrupt is generated when the correct SYNC Word is detected (if
SYNC Prime is set).
It is cleared by (1) reading the Status Register, and (2) setting RX / TX to logic “1”.
TX Idle: This is set and an Interrupt is generated when all loaded TX data and 1 “hang-bit” have been
transmitted.
It is cleared by (1) writing to the TX Data Buffer, and (2) setting RX / TX to logic “0”.
TX Data Ready: This is set and an Interrupt generated indicating that a byte of data should be written to the
TX Data Buffer.
It is cleared by (1) reading the Status Register and writing a byte of data to the TX Data Buffer, and (2) setting
RX / TX to logic “0”.
RX Data Ready: When this is set and an Interrupt generated, it indicates that the RX Data Buffer is full, and
that a byte of data is to be read from the RX Data buffer. This must be read within 8 bit periods.
It is cleared by (1) reading the Status Register and the RX Data buffer, and (2) setting the RX / TX to logic “1”/
RX Checksum True: This is set and an Interrupt is generated by a successful comparison of the received
and self-generated checksums.
It is cleared by (1) reading the Status Register and the RX Data Buffer, and (2) RX / TX being taken to logic
“1”
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
11
MX809
Reading
MSB
Bit 7
0
1
6
0
1
5
RX SYNC Detect
0
1
SYNC
4
0
1
3
0
1
2
0
1
1
0
1
0
0
1
Status Bits
Received First
Undefined
“0” or
“1”
Undefined
“0” or
“1”
RX SYNC Detect
SYNC
TX Idle
Idle
TX Data Ready
TX Date Ready
RX Checksum True
True
RX Data Ready
RX Data Ready
Table 8: Status Register
5.8
Interrupt Request
The conditions that cause interrupts to be output (if enabled by the Control Register) from the MX809 are:
TX Idle
TX Data Ready
RX SYNC Detect
RX Data Ready
RX SYNC Detect
The Status Register should be read to find the cause of the interrupt. Interrupts are cleared by (1) reading the
Status Register, or (2) changing the state of the RX / TX bit.
5.9
General Reset
Upon power-up, the bits in the MX809 Mode register and buffer will be random (either “0” or “1”). The
General Reset command (01H) will “reset” all microcircuits in the C-BUS and had the following effect on the
MX809.
All bits in the Control Register will be set to logic “0”. The Tx Out output will be set to VBIAS.
Note: The Status register, RX Data Buffer, TX Data Buffer, and SYNC Program register are not affected by
the General Reset Command.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
12
MX809
6 Application
6.1
6.1.1
Checksum Generation and Checking
Generation
The checksum generator takes the 48 bits from the 6 bytes loaded into the TX Data Buffer and divides them
into modulo-2 by the generating polynomial:
x15 + x14 + x13 + x11 + x4 + x2 + x1
It then takes the 15-bit remainder from the polynomial divider, inverts the last bit and appends an EVEN parity
bit generated from the initial 48 bits and the 15 bit remainder (with the last bit inverted). This 16 bit word is
used as the “Checksum”.
6.1.2
Checking
The checksum checker does two things:
1. It takes the first 63 bits of a received message, inverts bit 63, and divides them modulo-2 by the
generating polynomial:
x15 + x14 + x13 + x11 + x4 + x2 + x1
2. The 15 bits remaining in the polynomial divider are checked to make sure that they are all zero.
3. It generates an even parity bit from the first 63 bits of a received message and compares this bit with the
received parity (bit 64).
If the 15 bits in the polynomial divider are all zero and the two parity bits are equal, then the RX
Checksum True (Status Register bit 1) is set.
6.2
Modem Performance
Figure 3: Bit Error Rate vs. Signal-to-Noise Ratio
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
6.3
13
MX809
Modem Timing Information
Figure 4: Modem Timing
Notes:
1. The SYNC and SYNC detector searches the incoming bit stream starting at the end of the byte in which
SYNC / SYNC Prime was set.
2. After detection of a SYNC / SYNC word, the SYNC / SYNC Prime bits automatically go low (control bits 5
and 6: detector off.
3. The checksum checker is inhibited during the time SYNC / SYNC search is operating.
4. The Status Register will indicate whether SYNC or SYNC was detected here.
5. Any number of preamble bits can occur here.
6. Any number of bits can occur here.
7.
RX Freeformat set high.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
6.4
14
MX809
TX Timing
A – Address bytes
C – Checksum bytes
D – Data bytes
H – Hang bit
P – Preamble bytes
6.4.1
- Don’t care state
TX only – In TX, Preamble, and SYNC are
loaded as data from the microcontroller.
TX More Than One Message, SYNC Before Every Message, TX Checksum Enabled
RX/TX
TX OUTPUT
P1
P2
P
S1
S2
A1
A2
A3
A4
A5
S2
A1
A2
A3
A4
A5
A6
C1
A6
C2
S1
S2
D1
D2
D3
D4
D5
S1
D1
D2
D3
D4
D5
D6
D6
NOTE 6
IRQ
READ STATUS
REGISTER
TX DATA READY
WRITE TO
TX DATA BUFFER
P1
P2
S1
P
S2
CHECKSUM
ON/OFF
Figure 5: TX More Than One Message, SYNC Before Every Message, TX Checksum Enabled
Notes:
1. Preamble and SYNC bytes are loaded as data from the microcontroller.
2. The TX output will be held at bias level when no data is being transmitted.
3. TX byte synchronization is established by loading of the first preamble byte from the microcontroller.
4. Checksum must be turned off during preamble and SYNC words.
5. When RX / TX is low, TX output is at bias.
6. Any number of preamble bytes can occur here.
6.4.2
TX More Than One Message, TX Checksum Not Enabled.
RX/TX
TX OUTPUT
P1
P2
P
S1
S2
A1
A2
A3
NOTE 2
A4
A
S1
S2
D1
D2
D3
D4
NOTE 3
D
S1
S2
D1
S2
D1
D2
NOTE 3
IRQ
READ STATUS
REGISTER
TX DATA READY
WRITE TO
TX DATA BUFFER
P1
P2
P
S1
S2
A1
A2
A3
A4
A
S1
S2
D1
D2
D3
D4
D
S1
CHECKSUM
ON/OFF
Figure 6: TX More Than One Message, TX Checksum Not Enabled.
Notes:
1. Preamble, SYNC words and checksums are supplied by the microcontroller in this format as data bytes.
2. Any number of preamble bytes can occur here.
3. Any number of address/data bytes can occur here.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
6.4.3
15
MX809
TX One Message, TX Checksum Enabled
RX/TX
TX OUTPUT
P1
P2
P
S1
S2
A1
S2
A1
A2
A2
A3
A4
A5
A4
A5
A6
A6
C1
C2
H
NOTE 2
IRQ
READ STATUS
REGISTER
TX DATA READY
WRITE TO
TX DATA BUFFER
P1
P2
P
S1
A3
CHECKSUM
ON/OFF
TX IDLE
Figure 7: TX One Message, TX Checksum Enabled
Notes:
1. H is the “Hangover bit” (Logic1) appended to the transmitted message before transmission is terminated.
2. Any number of preamble bytes can occur here.
3. Transmission terminates after C1, C2, and H. Termination occurs when no further data bytes are written
to the TX Data Buffer.
6.4.4
TX One Message, TX Checksum Not Enabled.
RX/TX
TX OUTPUT
P1
P2
P
S1
S2
A1
A2
A3
A4
NOTE 2
A5
A
H
NOTE 3
IRQ
READ STATUS
REGISTER
TX DATA READY
WRITE TO
TX DATA BUFFER
P1
P2
P
S1
S2
A1
A2
A3
A4
A5
A
CHECKSUM
ON/OFF
TX IDLE
Figure 8: TX One Message, TX Checksum Not Enabled
Notes:
1. H is the “Hangover bit” (Logic1) appended to the transmitted message before transmission is terminated.
2. Any number of preamble bytes can occur here.
3. Any number of address/data bytes can occur here.
4. Transmission terminates when no further data bytes are loaded into the TX Data Buffer.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
6.5
16
MX809
RX Timing
A – Address bytes
C – Checksum bytes
D – Data bytes
H – Hang bit
P – Preamble bytes
6.5.1
- Don’t care state
TX only – In TX, Preamble, and SYNC are
loaded as data from the microcontroller.
RX SYNC / SYNC Required Before Every Message, Rx Checksum Not Enabled
RX/TX
P1
RX INPUT
P2
P
SYNC
A1
A2
NOTE 1
A3
A
NOTE 2
SYNC
A1 A2
A3
NOTE 3
IRQ
READ STATUS REGISTER
SYNC DETECT
(OR SYNC DETECT)
RX DATA READY
READ RX DATA BUFFER
A1
A2
A3
A
SYNC/SYNC PRIME
CHECKSUM ON/OFF
Figure 9: RX SYNC / SYNC Required Before Every Message, RX Checksum not Enabled
Notes:
1. Any number of preamble bits can occur here.
2. Any number of address/data bytes can occur here.
3. Any number of bits can occur here
4.
RX Freeformat set high.
6.5.2
RX Additional Data Follows Initial Address (6 Data & 2 Checksum Bytes) Data, RX checksum
Enabled
RX/TX
P1 P2
RX INPUT
P
SYNC
A1 A2 A3
A4
A5
A6
C1
C2
D1
D2
D3
D4
D5
D6
C1
C2
D1
NOTE 1
IRQ
READ STATUS
REGISTER
SYNC DETECT
(OR SYNC
DETECT)
RX DATA READY
READ RX
DATA BUFFER
RX CHECKSUM
TRUE
SYNC/SYNC
PRIME
CHECKSUM
ON/OFF
Figure 10: RX Additional Data Follows Initial Address (6 Data & 2 Checksum Bytes) Data , RX
Checksum Enabled
Notes:
1. Any number of preamble bits can occur here.
2.
RX Freeformat set high.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
17
MX809
7 Performance Specifications
7.1
Electrical Specifications
7.1.1
Absolute Maximum Limits
Exceeding these maximum ratings can result in damage to the device.
General
Supply (VDD-VSS)
Voltage on any pin to VSS
Current
VDD
VSS
Any other pin
J / LH Packages
Total allowable Power dissipation
at TAMB = 25C
Notes
Min.
-0.3
-0.3
Typ.
Max.
7.0
VDD + 0.3
Units
V
V
30
30
20
mA
mA
mA
800
mW
-30
-30
-20
10
Derating above 25C
mW/C above 25C
Operating Temperature
-40
85
C
Storage Temperature
-55
125
C
Table 9: Absolute Maximum Ratings
7.1.2
Operating Limits
Correct Operation of the device outside these limits is not implied.
Notes
Supply (VDD-VSS)
Operating Temperature
Xtal Frequency
Min.
4.5
-40
Typ.
5.0
Max.
5.5
85
4.032
Units
V
C
MHz
Table 10: Operating Limits
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
7.1.3
18
MX809
Operating Characteristics
For the following conditions unless otherwise specified.
VDD = 5.0V @ TAMB = 25C
Xtal/Clock Frequency = 4.032MHz, Audio Level 0dB ref. = 308mVRMS @ 1kHz
Bit Rate = 1200bps
Notes
Static Values
Supply Current
Enabled
Powersave
Dynamic Values
Digital Interface
Input Logic “1”
Input Logic “0”
Min.
Max.
5.0
2.0
Output Logic “1” (IOH = -120A)
Output Logic “0” (IOH = 360A)
Digital Input Current
VIN = Logic “1” or “0”
Digital Input Capacitance
Tri-State “OFF” Leakage Current
1
1
2
mA
mA
3.5
1.5
2, 3
0.4
V
1
1.0
1
8
7.5
4.0
A
pF
4.6
-4.0
100
Output Impedance
Transmitting Data
Not Transmitting Data
ROUT
k
M
5.0
k
dB
MHz
15.0
4.032
4
5
k
10.0
-9.0
-2.0
10.5
dB
7.0
1.0
10-4
10-8
99.0
99.5
%
%
6
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
10.0
1.0
On-Chip Xtal Oscillator
RIN
A
k
6.0
Gain
Frequency
Receiver
Signal Input Levels
Bit Error Rate
At 12dB SNR
At 20dB SNR
Synchronization at 12dB SNR
Probability of Bit 8 being correct
Probability of Bit 16 being correct
Units
V
V
V
Analog Impedance
Input Impedance
1998 MX-COM, Inc.
Typ.
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
19
MX809
Notes
Transmitter
Output Level
Output Level Variation
Output Distortion
Third Harmonic Distortion
Logic “1” Frequency
Logic “0” Frequency
Isochronous Distortion
1200Hz – 1800Hz
Min.
Typ.
Max.
0
-1.0
3.0
2.0
1200
1800
7
7
1800Hz – 1200Hz
Uncommitted Amplifier
Bandwidth
Gain
Input Impedance
Output Impedance
1.0
5.0
3.0
Units
dB
dB
%
%
Hz
Hz
25.0
40.0
s
20.0
40.0
s
200
50.0
kHz
dB
1.0
10.0
k
Table 11: Operating Characteristics
Operating Characteristics Notes:
1. Device control pins: Serial Clock, Command Data, Wake , and CS .
2. Reply Data output.
3.
IRQ output
4. For baud rate specified (1200 baud)
5. Signal-to-Noise Ratio = 50dB
6. The response time is measured using 10101010…101 signal input pattern at 230mVRMS (-2.5dB) with
noise.
7. Dependant upon Xtal tolerance.
8.
IRQ and Reply Data outputs for VSS < VOUT < VDD.
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
7.1.4
20
MX809
Timing
C-BUS Timing
tCSE
Chip Select Low to First Serial Clock Rising Edge
Min.
2.0
Typ.
Max.
Units
tCHS
Last Serial Clock Rising Edge to Chip Select High
4.0
tHIZ
Chip Select High to Reply Data High -Z
tCSOFF
Chip Select High time between transactions
2.0
s
tNXT
Inter-Byte Time
4.0
s
tCK
Serial Clock Period
2.0
s
s
s
2.0
Table 12: Timing Information
Notes:
1. Depending on the command, 1 or 2 bytes of Command Data is transmitted to the peripheral MSB (bit 7)
first, LSB (bit 0) last. Reply Data is read from the peripheral MXB (bit 7) first, LSB (bit 0) last.
2. Data is clocked into and out of the peripheral on the rising Serial Clock edge.
3. Loaded commands are acted upon at the end of each command.
4. To allow for differing microcontroller serial interface formats, C-BUS compatible ICs are able to work with
either polarity Serial Clock pulses.
t CSOFF
CHIP SELECT
t CSE
t NXT
SERIAL CLOCK
t CSH
t NXT
t CK
COMMAND DATA
7
6
5
4
3
2
1
MSB
0
7
LSB
MSB
6
5
4
3
2
1
0
LSB
7
6
4
3
2
1
0
LSB
FIRST DATA BYTE
ADDRESS/COMMAND
BYTE
5
MSB
LAST DATA BYTE
ä
REPLY DATA
7
Logic level is not important
6
5
4
3
2
1
0
MSB
LSB
FIRST REPLY DATA BYTE
7
MSB
6
5
4
3
2
1
ä
t HIZ
0
LSB
LAST REPLY DATA BYTE
Figure 11: C-BUS Timing Information
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
MSK Modem
7.2
21
MX809
Packages
A
Package Tolerances
B
E
E1
Y
T
PIN1
K
H
L
C
J1
J
P
DIM.
A
B
C
E
E1
H
J
J1
K
L
P
T
Y
MIN.
TYP.
MAX.
1.270 (32.26)
1.200 (30.48)
0.555 (14.04)
0.500 (12.70)
0.151 (3.84)
0.220 (5.59)
0.600 (15.24)
0.670 (17.02)
0.590 (14.99)
0.625 (15.88)
0.015 (0.38)
0.045 (1.14)
0.015 (0.38)
0.023 (0.58)
0.040 (1.02)
0.065 (1.65)
0.066 (1.67)
0.074 (1.88)
0.121 (3.07)
0.160 (4.05)
0.100 (2.54)
0.008 (0.20)
0.015 (0.38)
7°
NOTE : All dimensions in inches (mm.)
Angles are in degrees
Figure 12: 24-pin CERDIP Mechanical Outline: Order as part no. MX809J
E
B
C
Package Tolerances
K
Y
DA
W
J
W
T
PIN 1
H
P
G
DIM.
A
B
C
D
E
F
G
H
J
K
P
T
W
Y
MIN.
TYP.
MAX.
0.409 (10.40)
0.380 (9.61)
0.409 (10.40)
0.380 (9.61)
0.146 (3.70)
0.128 (3.25)
0.435 (11.05)
0.417 (10.60)
0.435 (11.05)
0.417 (10.60)
0.250 (6.35)
0.250 (6.35)
0.023 (0.58)
0.018 (0.45)
0.022 (0.55)
0.047 (1.19)
0.048 (1.22)
0.051 (1.30)
0.049 (1.24)
0.009 (0.22)
0.006 (0.152)
30°
45°
6°
NOTE : All dimensions in inches (mm.)
Angles are in degrees
F
Figure 13: 24-pin PLCC Mechanical Outline: Order as part no. MX809LH
1998 MX-COM, Inc.
www.mxcom.com Tel: 800 638 5577 336 744 5050 Fax: 336 744 5054
4800 Bethania Station Road, Winston-Salem, NC 27105-1201 USA
Doc. # 20480036.004
All trademarks and service marks are held by their respective companies.
CML Microcircuits
COMMUNICATION SEMICONDUCTORS
CML Product Data
In the process of creating a more global image, the three standard product semiconductor
companies of CML Microsystems Plc (Consumer Microcircuits Limited (UK), MX-COM, Inc
(USA) and CML Microcircuits (Singapore) Pte Ltd) have undergone name changes and, whilst
maintaining their separate new names (CML Microcircuits (UK) Ltd, CML Microcircuits (USA)
Inc and CML Microcircuits (Singapore) Pte Ltd), now operate under the single title CML
Microcircuits.
These companies are all 100% owned operating companies of the CML Microsystems Plc
Group and these changes are purely changes of name and do not change any underlying legal
entities and hence will have no effect on any agreements or contacts currently in force.
CML Microcircuits Product Prefix Codes
Until the latter part of 1996, the differentiator between products manufactured and sold from
MXCOM, Inc. and Consumer Microcircuits Limited were denoted by the prefixes MX and FX
respectively. These products use the same silicon etc. and today still carry the same prefixes.
In the latter part of 1996, both companies adopted the common prefix: CMX.
This notification is relevant product information to which it is attached.
CML Microcircuits (USA) [formerly MX-COM, Inc.] Product Textual Marking
On CML Microcircuits (USA) products, the ‘MX-COM’ textual logo is being replaced by a ‘CML’
textual logo.
Company contact information is as below:
CML Microcircuits
(UK)Ltd
CML Microcircuits
(USA) Inc.
CML Microcircuits
(Singapore)PteLtd
COMMUNICATION SEMICONDUCTORS
COMMUNICATION SEMICONDUCTORS
COMMUNICATION SEMICONDUCTORS
Oval Park, Langford, Maldon,
Essex, CM9 6WG, England
Tel: +44 (0)1621 875500
Fax: +44 (0)1621 875600
[email protected]
www.cmlmicro.com
4800 Bethania Station Road,
Winston-Salem, NC 27105, USA
Tel: +1 336 744 5050,
0800 638 5577
Fax: +1 336 744 5054
[email protected]
www.cmlmicro.com
No 2 Kallang Pudding Road, 09-05/
06 Mactech Industrial Building,
Singapore 349307
Tel: +65 7450426
Fax: +65 7452917
[email protected]
www.cmlmicro.com
D/CML (D)/2 May 2002