NetMos
Technology
Features
•
Single 5-V Operation
•
Low Power
•
PCI compatible single UART
•
Pin-to-Pin compatible to Nm9835
•
16 byte transmit-receive FIFO (UART)
•
Selectable receive trigger levels
•
Programmable baud rate generator
•
Modem control signals
•
5, 6, 7, 8 Bit characters selection
•
Even, Odd, No parity, or Force parity generations
•
Status report capability
•
Compatible with 16C550
•
On chip oscillator
•
Re-map function for legacy ports
•
Microsoft Compatible
•
128-pin VQFP package
Applications
•
Embedded applications
•
High speed modems
•
Monitoring equipment
•
Add on I/O cards
•
Serial networking
Nm9820
Single PCI UART
General Description
The Nm9820 is a PCI based single-channel high
performance UART. The Nm9820 offers 16 byte
transmit and receive FIFO compatible with standard
16C550. The Nm9820 perform serial-to-parallel
conversions on data received from a peripheral device,
and parallel-to-serial conversion on data received from
its CPU.
The Nm9820 is ideally suited for PC applications, such
as high-speed COM ports. The Nm9820 is available in
128-Pin QFP package, it is fabricated in an advanced
in submicron CMOS process to achieve low drain power
and high-speed requirements.
Ordering Information
Commercial Grade
Nm9820CV
128-VQFP
0° C to +70° C
Industrial Grade
Nm9820EV
128-VQFP
-40° C to +85° C
Rev. 1.0
Page 1-33
Nm9820
Single PCI UART
128-Pin VQFP Package
nRESET
EE-CLK
nDSRA
nDTRA
nCTSA
nRTSA
EE-DO
NetMos
Technology
EE-EN
EE-CS
nINTA
nCDA
EE-DI
AD29
128
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
AD30
127
AD31
126
GND
125
GND
nRIA
GND
VCC
VCC
RXA
N.C.
124
N.C.
CLK
122
TXA
123
121
120
119
118
117
116
115
114
113
112
111
110
109
108
107
106
105
104
103
102
101
100
99
98
97
96
95
94
93
92
91
90
89
88
87
86
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
VCC
AD28
AD27
AD26
AD25
AD24
GND
nC/BE3
IDSEL
VCC
AD23
AD22
AD21
AD20
AD19
AD18
AD17
AD16
VCC
GND
GND
nC/BE2
nFRAME
nIRDY
nTRDY
nDEVSEL
nSTOP
nLOCK
nPERR
nSERR
PAR
nC/BE1
GND
AD15
AD14
AD13
AD12
AD11
N.C.
N.C.
N.C.
GND
N.C.
N.C.
N.C.
N.C.
GND
N.C.
N.C.
N.C.
N.C.
VCC
GND
N.C.
N.C.
N.C.
N.C.
N.C.
VCC
N.C.
N.C.
N.C.
N.C.
GND
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
N.C.
VCC
N.C.
Nm9820CV
40
AD10
41
AD9
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
VCC
AD8
nC/BE0
GND
GND
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
VCC
3XCLK
6XCLK
BCLK
12XCLK
ACLK
GND
XTAL2
XTAL1
N.C.
N.C.
Page 1-34
Rev. 1.0
NetMos
Technology
Pin Name
CLK
nRESET
128
122
121
Type
I
I
Description
33 MHz PCI system clock input.
Nm9820
Single PCI UART
PCI System reset (avtice low). Resets all internal register, sequencers, and
signals to a consistent state. During reset condition AD31-0, nSER are three-
stated.
Multiplexed PCI address / data bus. A bus transaction consists of an address
phase followed by one or more data phase. During the address phase AD31-
0 contain a physical address. Write data is stable and valid when nIRDY and
nTRDY are asserted (active).
See AD31-29 description.
See AD31-29 description.
See AD31-29 description.
See AD31-29 description.
See AD31-29 description.
Frame is driven by the current master to indicate the beginning and duration
of an access. nFRAME is asserted to indicate a bus transaction is beginning.
While nFRAME is active, data transfer continues.
Initiator Ready. During a write, nIRDY asserted indicates that the initiator is
driving valid data onto the data bus. During a read, nIRDY asserted indicates
that the initiator is ready to accept data from the Nm9820.
Target Ready (three-state). It is asserted when Nm9820 is ready to complete
the current data phase.
Nm9820 asserts nSTOP to indicate that it wishes the initiator to stop the
transaction in process on the current data phase.
Lock indicates an atomic operation that my require multiple transactions to
complete.
Initialization Device Select. It is used as a chip select during configuration
read and writes transactions.
Device Select (three-state). Nm9820 asserts nDEVSEL when the Nm9820
has decoded its address.
AD31-29 126-128
I/O
AD28-24
AD23-16
AD15-11
AD10-8
AD7-0
nFRAME
2-6
11-18
34-38
40-42
46-53
23
I/O
I/O
I/O
I/O
I/O
I
nIRDY
24
I
nTRDY
nSTOP
nLOCK
IDSEL
nDEVSEL
25
27
28
9
26
O
O
I
I
O
Rev. 1.0
Page 1-35
Nm9820
Single PCI UART
Pin Name
nPERR
128
29
Type
O
Description
NetMos
Technology
Parity Error (three-state). Is used to report parity errors during all PCI
transactions except a Special Cycle. The minimum duration of nPERR is
one clock cycle.
System Error (open drain). This pin goes low when address parity errors are
detected.
Even Parity. Parity is even parity across AD31-0 and nC/BE3-0. PAR is stable
and valid one clock after the address phase. For data phase PAR is stable
and valid one clock after either nIRDY is asserted on a write transaction or
nTRDY is asserted on a read transaction.
Bus Command and Byte Enable. During the address phase of a transaction,
nC/BE3-0 defines the bus command. During data phase nC/BE3-0 are used
as Byte Enables.nC/BE3 applies to byte “3”.
Bus Command and Byte Enable. During the address phase of a transaction,
nC/BE3-0 defines the bus command. During data phase nC/BE3-0 are used
as Byte Enables. nC/BE2 applies to byte “2”.
Bus Command and Byte Enable. During the address phase of a transaction,
nC/BE3-0 defines the bus command. During data phase nC/BE3-0 are used
as Byte Enables. nC/BE1 applies to byte “1”.
Bus Command and Byte Enable. During the address phase of a transaction,
nC/BE3-0 defines the bus command. During data phase nC/BE3-0 are used
as Byte Enables. nC/BE0 applies to byte “0”.
PCI active low interrupt output (open-drain). This signal goes low (active)
when an interrupt condition occurs.
External EE-Prom chip select (active high). After power on reset, Nm9820
reads the EE-Prom and loads the read-only configuration registers
sequentially from the first 64 bytes in the EE-Prom.
External EE-Prom clock.
External EE-Prom data input.
External EE-Prom data output.
Enable/Disable external EEprom (active high, internal pull-up). External
EEprom can be disabled when this pin is tied to GND or pulled low. When
external EEprom is disabled, the default values for Nm9820 will be loaded
into PCI configuration register.
nSERR
PAR
30
31
O
I/O
nC/BE3
8
I
nC/BE2
22
I
nC/BE1
32
I
nC/BE0
43
I
nINTA
EE-CS
120
115
O
O
EE-CLK
EE-DI
EE-DO
EE-EN
116
118
117
123
O
I
O
I
Page 1-36
Rev. 1.0
NetMos
Technology
Pin Name
XTAL1
128
62
Type
I
Description
Nm9820
Single PCI UART
Crystal oscillator input or External clock input pin (22.1184 MHz). This signal
input is used in conjunction with XTAL2 to form a feedback circuit for the
internal timing. Two external capacitors (10pF) connected from each side of
the XTAL1 and XTAL2 to GND is required to form a crystal oscillator circuit.
Crystal oscillator output. See XTAL1 description.
External clock or crystal oscillator clock divide by 12 output (1.8432 MHz
standard PC UART clock for 115.2k data rate).
External clock or crystal oscillator clock divide by 6 output (3.6864 MHz PC
UART clock for 230.4k data rate).
External clock or crystal oscillator clock divide by 3 output (7.3728 MHz UART
clock for 460.8k data rate).
UART-A clock input. ACLK should be connected to external clock source or
one of the 12XCLK, 6XCLK, 3XCLK output pins of the Nm9820.
UART-B clock input. BCLK should be connected to external clock source or
one of the 12XCLK, 6XCLK, 3XCLK output pins of the Nm9820.
UART-A Serial data output.
Active low, UART-A request-to-send signal. It is set to high (in active) after a
hardware reset or during internal loop-back mode. When low, this indicates
that Modem or data set is ready to establish a communication link. nRTSA
has no effect on the transmitter or receiver.
Active low, UART-A data-terminal-ready signal. It is set to high (in active)
after a hardware reset or during internal loop-back mode. When low, this
output indicates to the Modem or data set that the UART-A is ready to establish
a communication link. nDTRA has no effect on the transmitter or receiver.
UART-A, Serial data input.
Active low, UART-A clear-to-send signal. When low this indicates that Modem
or data set is ready to exchange data. nCTSA has no effect on the transmitter.
Active low, UART-A data-set-ready signal.
Active low, UART-A Carrier-detect signal. When low this indicates that Modem
or data set has detected the data carrier. nCDA has no effect on the
transmitter.
Active low, UART-A ring-detect signal.
Page 1-37
XTAL2
12XCLK
6XCLK
3XCLK
ACLK
BCLK
TXA
nRTSA
61
58
56
55
59
57
105
107
O
O
O
O
I
I
O
O
nDTRA
106
O
RXA
nCTSA
nDSRA
nCDA
109
111
110
112
I
I
I
I
nRIA
Rev. 1.0
113
I
FPGA/CPLD
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