DATASHEET

X9521
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Dual DCP, EEPROM Memory
September 21, 2010
Fiber Channel/Gigabit Ethernet Laser
Diode Control for Fiber Optic Modules
FN8207.2
DESCRIPTION
The X9521 combines two Digitally Controlled Potentiometers (DCP’s), and integrated EEPROM with Block
LockTM protection. All functions of the X9521 are
accessed by an industry standard 2-Wire serial interface.
FEATURES
• Two Digitally Controlled Potentiometers (DCP’s)
—100 Tap - 10kΩ
—256 Tap - 100kΩ
—Non-Volatile
—Write Protect Function
• 2kbit EEPROM Memory with Write Protect & Block
LockTM
• 2-Wire industry standard Serial Interface
—Complies to the Gigabit Interface Converter
(GBIC) specification
• Single Supply Operation
—2.7V to 5.5V
• Hot Pluggable
• 20 Ld TSSOP
The DCP’s of the X9521 may be utilized to control the
bias and modulation currents of the laser diode in a Fiber
Optic module. The 2kbit integrated EEPROM may be
used to store module definition data.
The features of the X9521 are ideally suited to simplifying
the design of fiber optic modules which comply to the Gigabit Interface Converter (GBIC) specification. The integration of these functions into one package significantly
reduces board area, cost and increases reliability of laser
diode modules.
BLOCK DIAGRAM
RH1
WIPER
COUNTER
REGISTER
RW1
RL1
8
WP
PROTECT LOGIC
7 - BIT
NONVOLATILE
MEMORY
RH2
CONSTAT
SDA
SCL
DATA
REGISTER
COMMAND
DECODE &
CONTROL
LOGIC
4
REGISTER
WIPER
COUNTER
REGISTER
RW2
RL2
2kbit
8 - BIT
NONVOLATILE
MEMORY
EEPROM
ARRAY
THRESHOLD
RESET LOGIC
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
©2000 Intersil Inc., Patents Pending. Copyright Intersil Americas Inc. 2006. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
X9521
Ordering Information
PART NUMBER
PART MARKING
PRESET (FACTORY SHIPPED) VTRIPx
THRESHOLD LEVELS (x = 2, 3)
TEMP RANGE (°C)
PACKAGE
X9521V20I-A
X9521VIA
Optimized for 3.3V system monitoring
-40 to +85
20 Ld TSSOP
X9521V20I-B
X9521VIB
Optimized for 5V system monitoring
-40 to +85
20 Ld TSSOP
X9521V20IZ-A (Note)
X9521VZIA
Optimized for 3.3V system monitoring
-40 to +85
20 Ld TSSOP (Pb-free)
X9521V20IZ-B (Note)
X9521VZIB
Optimized for 5V system monitoring
-40 to +85
20 Ld TSSOP (Pb-free)
NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate
termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL
classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
PIN CONFIGURATION
20 Pin TSSOP
RH2
RW2
RL2
NC
NC
NC
WP
1
2
3
4
5
6
SCL
7
8
SDA
VSS
9
10
20
19
18
17
16
15
14
13
12
11
Vcc
NC
NC
NC
NC
NC
NC
RH1
RW1
RL1
PIN ASSIGNMENT
Pin
Name
1
RH2
Function
Connection to end of resistor array for (the 256 Tap) DCP 2.
2
Rw2
Connection to terminal equivalent to the “Wiper” of a mechanical potentiometer for DCP 2.
3
RL2
Connection to other end of resistor array for (the 256 Tap) DCP2.
7
WP
Write Protect Control Pin. WP pin is a TTL level compatible input. When held HIGH, Write Protection is
enabled. In the enabled state, this pin prevents all nonvolatile “write” operations. Also, when the Write Protection is enabled, and the device Block Lock feature is active (i.e. the Block Lock bits are NOT [0,0]), then
no “write” (volatile or nonvolatile) operations can be performed in the device (including the wiper position
of any of the integrated Digitally Controlled Potentiometers (DCPs). The WP pin uses an internal “pulldown” resistor, thus if left floating the write protection feature is disabled.
8
SCL
Serial Clock. This is a TTL level compatible input pin used to control the serial bus timing for data input
and output.
9
SDA
Serial Data. SDA is a bidirectional TTL level compatible pin used to transfer data into and out of the device. The SDA pin input buffer is always active (not gated). This pin requires an external pull up resistor.
10
Vss
Ground.
11
RL1
Connection to other end of resistor for (the 100 Tap) DCP 1.
12
Rw1
Connection to terminal equivalent to the “Wiper” of a mechanical potentiometer for DCP 1
13
RH1
Connection to end of resistor array for (the 100 Tap) DCP 1.
20
Vcc
Supply Voltage.
4, 5, 6,
14, 15,
16, 17,
18, 19
NC
No connect.
2
FN8207.2
September 21, 2010
X9521
SCL
SDA
Start
Figure 2.
Stop
Valid Start and Stop Conditions
SCL
SDA
Data Stable
Figure 1.
Data Stable
Valid Data Changes on the SDA Bus
PRINCIPLES OF OPERATION
SERIAL INTERFACE
Serial Interface Conventions
The device supports a bidirectional bus oriented protocol.
The protocol defines any device that sends data onto the
bus as a transmitter, and the receiving device as the
receiver. The device controlling the transfer is called the
master and the device being controlled is called the
slave. The master always initiates data transfers, and
provides the clock for both transmit and receive operations. Therefore, the X9521 operates as a slave in all
applications.
Serial Clock and Data
Data states on the SDA line can change only while SCL
is LOW. SDA state changes while SCL is HIGH are
reserved for indicating START and STOP conditions.
See Figure 1. On power-up of the X9521, the SDA pin is
in the input mode.
Serial Start Condition
All commands are preceded by the START condition,
which is a HIGH to LOW transition of SDA while SCL is
HIGH. The device continuously monitors the SDA and
SCL lines for the START condition and does not respond
to any command until this condition has been met. See
Figure 2.
3
Data Change
Serial Stop Condition
All communications must be terminated by a STOP
condition, which is a LOW to HIGH transition of SDA
while SCL is HIGH. The STOP condition is also used to
place the device into the Standby power mode after a
read sequence. A STOP condition can only be issued
after the transmitting device has released the bus. See
Figure 2.
Serial Acknowledge
An ACKNOWLEDGE (ACK) is a software convention
used to indicate a successful data transfer. The transmitting device, either master or slave, will release the bus
after transmitting eight bits. During the ninth clock cycle,
the receiver will pull the SDA line LOW to ACKNOWLEDGE that it received the eight bits of data. Refer to
Figure 3.
The device will respond with an ACKNOWLEDGE after
recognition of a START condition if the correct Device
Identifier bits are contained in the Slave Address Byte. If
a write operation is selected, the device will respond with
an ACKNOWLEDGE after the receipt of each subsequent eight bit word.
In the read mode, the device will transmit eight bits of
data, release the SDA line, then monitor the line for an
ACKNOWLEDGE. If an ACKNOWLEDGE is detected
and no STOP condition is generated by the master, the
device will continue to transmit data. The device will terminate further data transmissions if an ACKNOWLEDGE
is not detected. The master must then issue a STOP
condition to place the device into a known state.
FN8207.2
September 21, 2010
X9521
SCL
from
Master
Data Output
from
Transmitter
Data Output
from
Receiver
1
8
9
Start
Figure 3.
Acknowledge
Acknowledge Response From Receiver
DEVICE INTERNAL ADDRESSING
Addressing Protocol Overview
The user addressable internal components of the X9521
can be split up into three main parts:
—Two Digitally Controlled Potentiometers (DCPs)
—EEPROM array
—Control and Status (CONSTAT) Register
Depending upon the operation to be performed on each
of these individual parts, a 1, 2 or 3 Byte protocol is used.
All operations however must begin with the Slave
Address Byte being issued on the SDA pin. The Slave
address selects the part of the X9521 to be addressed,
and specifies if a Read or Write operation is to be performed.
It should be noted that in order to perform a write operation to either a DCP or the EEPROM array, the Write
Enable Latch (WEL) bit must first be set (See “BL1, BL0:
Block Lock protection bits - (Nonvolatile)” on page 12.)
Slave Address Byte
Following a START condition, the master must output a
Slave Address Byte (Refer to Figure 4.). This byte consists of three parts:
—The Device Type Identifier which consists of the most
significant four bits of the Slave Address (SA7 - SA4).
The Device Type Identifier must always be set to 1010
in order to select the X9521.
—The next three bits (SA3 - SA1) are the Internal Device
Address bits. Setting these bits to 000 internally
selects the EEPROM array, while setting these bits to
111 selects the DCP structures in the X9521. The
CONSTAT Register may be selected using the Internal Device Address 010.
—The Least Significant Bit of the Slave Address (SA0)
Byte is the R/W bit. This bit defines the operation to be
performed on the device being addressed (as defined
in the bits SA3 - SA1). When the R/W bit is “1”, then a
READ operation is selected. A “0” selects a WRITE
operation (Refer to Figure 4.)
SA7
SA6 SA5
1 0 1
SA3
SA2
SA1
0
DEVICE TYPE
IDENTIFIER
SA0
R/W
READ /
WRITE
INTERNAL
DEVICE
ADDRESS
Internal Address
(SA3 - SA1)
Internally Addressed
Device
000
EEPROM Array
010
CONSTAT Register
111
DCP
Bit SA0
Operation
0
WRITE
1
READ
Figure 4.
4
SA4
Slave Address Format
FN8207.2
September 21, 2010
X9521
Nonvolatile Write Acknowledge Polling
After a nonvolatile write command sequence (for either
the EEPROM array, the Non Volatile Memory of a DCP
(NVM), or the CONSTAT Register) has been correctly
issued (including the final STOP condition), the X9521
initiates an internal high voltage write cycle. This cycle
typically requires 5 ms. During this time, no further Read
or Write commands can be issued to the device. Write
Acknowledge Polling is used to determine when this high
voltage write cycle has been completed.
To perform acknowledge polling, the master issues a
START condition followed by a Slave Address Byte. The
Slave Address issued must contain a valid Internal
Device Address. The LSB of the Slave Address (R/W)
can be set to either 1 or 0 in this case. If the device is still
busy with the high voltage cycle then no ACKNOWLEDGE will be returned. If the device has completed the
write operation, an ACKNOWLEDGE will be returned
and the host can then proceed with a read or write operation. (Refer to Figure 5.).
RHx
N
WIPER
COUNTER
REGISTER
(WCR)
DECODER
“WIPER”
FET
SWITCHES
RESISTOR
ARRAY
2
NON
VOLATILE
MEMORY
(NVM)
1
0
RLx
RWx
Figure 6.
DCP Internal Structure
DIGITALLY CONTROLLED POTENTIOMETERS
DCP Functionality
The X9521 includes two independent resistor arrays.
These arrays respectively contain 99 and 255 discrete
resistive segments that are connected in series. The
physical ends of each array are equivalent to the fixed
terminals of a mechanical potentiometer (RHx and RLx
inputs - where x = 1,2).
Byte load completed
by issuing STOP.
Enter ACK Polling
Issue START
Issue Slave Address
Byte (Read or Write)
Issue STOP
NO
ACK
returned?
YES
High Voltage Cycle
NO
Issue STOP
complete. Continue
command sequence?
YES
Continue normal
Read or Write
command sequence
At both ends of each array and between each resistor
segment there is a CMOS switch connected to the wiper
(Rwx) output. Within each individual array, only one
switch may be turned on at any one time. These
switches are controlled by the Wiper Counter Register
(WCR) (See Figure 6). The WCR is a volatile register.
On power-up of the X9521, wiper position data is automatically loaded into the WCR from its associated Non
Volatile Memory (NVM) Register. The Table below
shows the Initial Values of the DCP WCR’s before the
contents of the NVM is loaded into the WCR.
DCP
Initial Values Before Recall
R1 / 100 TAP
VL / TAP = 0
R2 / 256 TAP
VH / TAP = 255
PROCEED
Figure 5.
Acknowledge Polling Sequence
5
FN8207.2
September 21, 2010
X9521
Vcc
Vcc (Max.)
VTRIP
ttrans
tpu
t
0
Maximum Wiper Recall time
Figure 7.
DCP Power-up
The data in the WCR is then decoded to select and
enable one of the respective FET switches. A “make
before break” sequence is used internally for the FET
switches when the wiper is moved from one tap position
to another.
Hot Pluggability
Figure 7 shows a typical waveform that the X9521 might
experience in a Hot Pluggable situation. On power-up,
Vcc applied to the X9521 may exhibit some amount of
ringing, before it settles to the required value.
The device is designed such that the wiper terminal
(RWx) is recalled to the correct position (as per the last
stored in the DCP NVM), when the voltage applied to
Vcc exceeds VTRIP for a time exceeding tpu.
Therefore, if ttrans is defined as the time taken for Vcc to
settle above VTRIP (Figure 7): then the desired wiper terminal position is recalled by (a maximum) time: ttrans +
tpu. It should be noted that ttrans is determined by system hot plug conditions.
DCP Operations
In total there are three operations that can be performed
on any internal DCP structure:
—DCP Nonvolatile Write
—DCP Volatile Write
—DCP Read
A nonvolatile write to a DCP will change the “wiper
position” by simultaneously writing new data to the
associated WCR and NVM. Therefore, the new “wiper
position” setting is recalled into the WCR after Vcc of the
X9521 is powered down and then powered back up.
A volatile write operation to a DCP however, changes the
“wiper position” by writing new data to the associated
WCR only. The contents of the associated NVM register
6
remains unchanged. Therefore, when Vcc to the device
is powered down then back up, the “wiper position”
reverts to that last position written to the DCP using a
nonvolatile write operation.
Both volatile and nonvolatile write operations are
executed using a three byte command sequence: (DCP)
Slave Address Byte, Instruction Byte, followed by a Data
Byte (See Figure 9).
A DCP Read operation allows the user to “read out” the
current “wiper position” of the DCP, as stored in the
associated WCR. This operation is executed using the
Random Address Read command sequence, consisting
of the (DCP) Slave Address Byte followed by an
Instruction Byte and the Slave Address Byte again (Refer
to Figure 11.).
Instruction Byte
While the Slave Address Byte is used to select the DCP
devices, an Instruction Byte is used to determine which
DCP is being addressed.
The Instruction Byte (Figure 8) is valid only when the
Device Type Identifier and the Internal Device
Address bits of the Slave Address are set to
1010111. In this case, the two Least Significant Bit’s
(I1 - I0) of the Instruction Byte are used to select the
particular DCP (0 - 2). In the case of a Write to any of
the DCPs (i.e. the LSB of the Slave Address is 0), the
Most Significant Bit of the Instruction Byte (I7), determines the Write Type (WT) performed.
If WT is “1”, then a Nonvolatile Write to the DCP occurs.
In this case, the “wiper position” of the DCP is changed
by simultaneously writing new data to the associated
WCR and NVM. Therefore, the new “wiper position” setting is recalled into the WCR after Vcc of the X9521 has
been powered down then powered back up
FN8207.2
September 21, 2010
X9521
I7
WT
I6
I5
I4
I3
I2
0
0
0
0
0
I1
P1
WRITE TYPE
volatile or nonvolatile. If the Instruction Byte format is
valid, another ACKNOWLEDGE is then returned by the
X9521.
I0
P0
Following the Instruction Byte, a Data Byte is issued to
the X9521 over SDA. The Data Byte contents is latched
into the WCR of the DCP on the first rising edge of the
clock signal, after the LSB of the Data Byte (D0) has
been issued on SDA (See Figure 25).
DCP SELECT
WT†
Description
0
Select a Volatile Write operation to be performed
on the DCP pointed to by bits P1 and P0
1
Select a Nonvolatile Write operation to be performed on the DCP pointed to by bits P1 and P0
The Data Byte determines the “wiper position” (which
FET switch of the DCP resistive array is switched ON) of
the DCP. The maximum value for the Data Byte depends
upon which DCP is being addressed (see Table below).
†This bit has no effect when a Read operation is being performed.
Figure 8.
P1 - P0
Instruction Byte Format
If WT is “0” then a DCP Volatile Write is performed. This
operation changes the DCP “wiper position” by writing
new data to the associated WCR only. The contents of
the associated NVM register remains unchanged. Therefore, when Vcc to the device is powered down then back
up, the “wiper position” reverts to that last written to the
DCP using a nonvolatile write operation.
In order to perform a write operation on a particular DCP,
the Write Enable Latch (WEL) bit of the CONSTAT Register must first be set (See “BL1, BL0: Block Lock protection bits - (Nonvolatile)” on page 12.)
The Slave Address Byte 10101110 specifies that a Write
to a DCP is to be conducted. An ACKNOWLEDGE is
returned by the X9521 after the Slave Address, if it has
been received correctly.
0
1
1
1
0
A WT
C
K
0
0
0
0
1
x=1
100
Reserved
Refer to Appendix 1
1
0
x=2
256
FFh
1
1
Reserved
0
0
P1 P0
A
C
K
D7 D6 D5 D4 D3 D2 D1 D0
INSTRUCTION BYTE
SLAVE ADDRESS BYTE
Figure 9.
7
0
0
It should be noted that all writes to any DCP of the X9521
are random in nature. Therefore, the Data Byte of consecutive write operations to any DCP can differ by an
arbitrary number of bits. Also, setting the bits (P1 = 0,
Next, an Instruction Byte is issued on SDA. Bits P1 and
P0 of the Instruction Byte determine which WCR is to be
written, while the WT bit determines if the Write is to be
1
Max. Data Byte
For DCP2 (256 Tap), the Data Byte maps one to one to
the “wiper position” of the DCP “wiper terminal”. Therefore, the Data Byte 00001111 (1510) corresponds to setting the “wiper terminal” to tap position 15. Similarly, the
Data Byte 00011100 (2810) corresponds to setting the
“wiper terminal” to tap position 28. The mapping of the
Data Byte to “wiper position” data for DCP1 (100 Tap), is
shown in “APPENDIX 1” . An example of a simple C language function which “translates” between the tap position (decimal) and the Data Byte (binary) for DCP1, is
given in “APPENDIX 2” .
A write to DCPx (x = 1,2) can be performed using the
three byte command sequence shown in Figure 9.
0
# Taps
Using a Data Byte larger than the values specified above
results in the “wiper terminal” being set to the highest tap
position. The “wiper position” does NOT roll-over to the
lowest tap position.
DCP Write Operation
S 1
T
A
R
T
DCPx
DATA BYTE
A
C
K
S
T
O
P
DCP Write Command Sequence
FN8207.2
September 21, 2010
X9521
Signals from
the Master
SDA Bus
S
t
a
r
t
S
t
o
p
(2 < n < 16)
Address
Byte
Slave
Address
Data
(n)
Data
(1)
1 01 00 00 0
A
C
K
Signals from
the Slave
A
C
K
A
C
K
A
C
K
Figure 10. EEPROM Page Write Operation
an Instruction Byte is issued on SDA. Bits P1 - P0 of the
Instruction Byte determine which DCP “wiper position” is
to be read. In this case, the state of the WT bit is “don’t
care”. If the Instruction Byte format is valid, then another
ACKNOWLEDGE is returned by the X9521.
P0 = 0) or (P1 = 1, P0 = 1) are reserved sequences, and
will result in no ACKNOWLEDGE after sending an
Instruction Byte on SDA.
The factory default setting of all “wiper position” settings
is with 00h stored in the NVM of the DCPs. This corresponds to having the “wiper teminal” RWX (x=1,2) at the
“lowest” tap position, Therefore, the resistance between
RWX and RLX is a minimum (essentially only the Wiper
Resistance, RW).
Following this ACKNOWLEDGE, the master immediately
issues another START condition and a valid Slave
address byte with the R/W bit set to 1. Then the X9521
issues an ACKNOWLEDGE followed by Data Byte, and
finally, the master issues a STOP condition. The Data
Byte read in this operation, corresponds to the “wiper
position” (value of the WCR) of the DCP pointed to by
bits P1 and P0.
DCP Read Operation
A read of DCPx (x = 1,2) can be performed using the
three byte random read command sequence shown in
Figure 11.
It should be noted that when reading out the data byte for
DCP1 (100 Tap), the upper most significant bit is an
“unknown”. For DCP2 (256 Tap) however, all bits of the
data byte are relevant (See Figure 11).
The master issues the START condition and the Slave
Address Byte 10101110 which specifies that a “dummy”
write” is to be conducted. This “dummy” write operation
sets which DCP is to be read (in the preceding Read
operation). An ACKNOWLEDGE is returned by the
X9521 after the Slave Address if received correctly. Next,
Signals from
the Master
SDA Bus
WRITE Operation
S
t
a
r
t
Slave
Address
Instruction
Byte
10101110
W 00000 P P
1 0
T
A
C
K
Signals from
the Slave
S
t
a
r
t
READ Operation
Slave
Address
Data Byte
S
t
o
p
10101111
A
C
K
A
C
K
DCPx
-
x=1
“Dummy” write
x=2
MSB
LSB
“-” = DON’T CARE
Figure 11.
8
DCP Read Sequence
FN8207.2
September 21, 2010
X9521
Signals from
the Master
SDA Bus
Signals from
the Slave
S
t
a
r
t
WRITE Operation
Address
Byte
Slave
Address
S
t
o
p
Data
Byte
1 01 00 00 0
Internal
Device
Address
A
C
K
A
C
K
A
C
K
Figure 12. EEPROM Byte Write Sequence
EEPROM Page Write
2kbit EEPROM ARRAY
Operations on the 2kbit EEPROM Array, consist of either
1, 2 or 3 byte command sequences. All operations on the
EEPROM must begin with the Device Type Identifier of
the Slave Address set to 1010000. A Read or Write to
the EEPROM is selected by setting the LSB of the Slave
Address to the appropriate value R/W (Read = “1”, Write
= ”0”).
In some cases when performing a Read or Write to the
EEPROM, an Address Byte may also need to be specified. This Address Byte can contain the values 00h to
FFh.
EEPROM Byte Write
In order to perform an EEPROM Byte Write operation to
the EEPROM array, the Write Enable Latch (WEL) bit of
the CONSTAT Register must first be set (See “BL1, BL0:
Block Lock protection bits - (Nonvolatile)” on page 12.)
For a write operation, the X9521 requires the Slave
Address Byte and an Address Byte. This gives the
master access to any one of the words in the array. After
receipt of the Address Byte, the X9521 responds with an
ACKNOWLEDGE, and awaits the next eight bits of data.
After receiving the 8 bits of the Data Byte, it again
responds with an ACKNOWLEDGE. The master then
terminates the transfer by generating a STOP condition,
at which time the X9521 begins the internal write cycle to
the nonvolatile memory (See Figure 12). During this
internal write cycle, the X9521 inputs are disabled, so it
does not respond to any requests from the master. The
SDA output is at high impedance. A write to a region of
EEPROM memory which has been protected with the
Block-Lock feature (See “BL1, BL0: Block Lock
protection bits - (Nonvolatile)” on page 12.), suppresses
the ACKNOWLEDGE bit after the Address Byte.
9
In order to perform an EEPROM Page Write operation to
the EEPROM array, the Write Enable Latch (WEL) bit of
the CONSTAT Register must first be set (See “BL1, BL0:
Block Lock protection bits - (Nonvolatile)” on page 12.)
The X9521 is capable of a page write operation. It is initiated in the same manner as the byte write operation; but
instead of terminating the write cycle after the first data
byte is transferred, the master can transmit an unlimited
number of 8-bit bytes. After the receipt of each byte, the
X9521 responds with an ACKNOWLEDGE, and the
address is internally incremented by one. The page
address remains constant. When the counter reaches
the end of the page, it “rolls over” and goes back to ‘0’ on
the same page.
For example, if the master writes 12 bytes to the page
starting at location 11 (decimal), the first 5 bytes are written to locations 11 through 15, while the last 7 bytes are
written to locations 0 through 6. Afterwards, the address
counter would point to location 7. If the master supplies
more than 16 bytes of data, then new data overwrites the
previous data, one byte at a time (See Figure 13).
The master terminates the Data Byte loading by issuing
a STOP condition, which causes the X9521 to begin the
nonvolatile write cycle. As with the byte write operation,
all inputs are disabled until completion of the internal
write cycle. See Figure 10 for the address, ACKNOWLEDGE, and data transfer sequence.
Stops and EEPROM Write Modes
Stop conditions that terminate write operations must be
sent by the master after sending at least 1 full data byte
and receiving the subsequent ACKNOWLEDGE signal.
If the master issues a STOP within a Data Byte, or before
the X9521 issues a corresponding ACKNOWLEDGE,
the X9521 cancels the write operation. Therefore, the
contents of the EEPROM array does not change.
FN8207.2
September 21, 2010
X9521
5 bytes
5 bytes
7 bytes
address
1110
address
= 6 10
address
1510
address pointer
ends here
Addr = 710
Figure 13. Example: Writing 12 bytes to a 16-byte page starting at location 11.
Signals from
the Master
SDA Bus
S
t
a
r
t
S
t
o
p
Slave
Address
1 01 0 0 0 0 1
Signals from
the Slave
A
C
K
Data
Figure 14. Current EEPROM Address Read Sequence
EEPROM Array Read Operations
Read operations are initiated in the same manner as
write operations with the exception that the R/W bit of the
Slave Address Byte is set to one. There are three basic
read operations: Current EEPROM Address Read, Random EEPROM Read, and Sequential EEPROM Read.
Current EEPROM Address Read
Internally the device contains an address counter that
maintains the address of the last word read incremented
by one. Therefore, if the last read was to address n, the
next read operation would access data from address
n+1. On power-up, the address of the address counter is
undefined, requiring a read or write operation for initialization.
Upon receipt of the Slave Address Byte with the R/W bit
set to one, the device issues an ACKNOWLEDGE and
then transmits the eight bits of the Data Byte. The master
terminates the read operation when it does not respond
with an ACKNOWLEDGE during the ninth clock and then
issues a STOP condition (See Figure 14 for the address,
ACKNOWLEDGE, and data transfer sequence).
10
It should be noted that the ninth clock cycle of the read
operation is not a “don’t care.” To terminate a read operation, the master must either issue a STOP condition during the ninth cycle or hold SDA HIGH during the ninth
clock cycle and then issue a STOP condition.
Another important point to note regarding the “Current
EEPROM Address Read” , is that this operation is not
available if the last executed operation was an access to
a DCP or the CONSTAT Register (i.e.: an operation
using the Device Type Identifier 1010111 or 1010010).
Immediately after an operation to a DCP or CONSTAT
Register is performed, only a “Random EEPROM Read”
is available. Immediately following a “Random EEPROM
Read” , a “Current EEPROM Address Read” or “Sequential EEPROM Read” is once again available (assuming
that no access to a DCP or CONSTAT Register occur in
the interim).
FN8207.2
September 21, 2010
X9521
WRITE Operation
S
t
a
r
t
Signals from
the Master
SDA Bus
Slave
Address
Address
Byte
S
t
o
p
10100001
10 1 0 0 0 0 0
A
C
K
Signals from
the Slave
READ Operation
S
t
Slave
a
r Address
t
A
C
K
A
C
K
Data
“Dummy” Write
Figure 15. Random EEPROM Address Read Sequence
Random EEPROM Read
Random read operation allows the master to access any
memory location in the array. Prior to issuing the Slave
Address Byte with the R/W bit set to one, the master
must first perform a “dummy” write operation. The master
issues the START condition and the Slave Address Byte,
receives an ACKNOWLEDGE, then issues an Address
Byte. This “dummy” Write operation sets the address
pointer to the address from which to begin the random
EEPROM read operation.
After the X9521 acknowledges the receipt of the Address
Byte, the master immediately issues another START
condition and the Slave Address Byte with the R/W bit
set to one. This is followed by an ACKNOWLEDGE from
the X9521 and then by the eight bit word. The master terminates the read operation by not responding with an
ACKNOWLEDGE and instead issuing a STOP condition
(Refer to Figure 15.).
A similar operation called “Set Current Address” also
exists. This operation is performed if a STOP is issued
instead of the second START shown in Figure 15. In this
case, the device sets the address pointer to that of the
Signals from
the Master
SDA Bus
Slave
Address
Address Byte, and then goes into standby mode after the
STOP bit. All bus activity will be ignored until another
START is detected.
Sequential EEPROM Read
Sequential reads can be initiated as either a current
address read or random address read. The first Data
Byte is transmitted as with the other modes; however,
the master now responds with an ACKNOWLEDGE,
indicating it requires additional data. The X9521 continues to output a Data Byte for each ACKNOWLEDGE
received. The master terminates the read operation by
not responding with an ACKNOWLEDGE and instead
issuing a STOP condition.
The data output is sequential, with the data from
address n followed by the data from address n + 1. The
address counter for read operations increments through
the entire memory contents to be serially read during
one operation. At the end of the address space the
counter “rolls over” to address 00h and the device continues to output data for each ACKNOWLEDGE
received (Refer to Figure 16.).
A
C
K
A
C
K
A
C
K
S
t
o
p
0 0 01
A
C
K
Signals from
the Slave
Data
(1)
Data
(2)
Data
(n - 1)
Data
(n)
(n is any integer greater than 1)
Figure 16. Sequential EEPROM Read Sequence
11
FN8207.2
September 21, 2010
X9521
CS7
CS6
CS5
CS4
CS3
CS2
CS1
CS0
0
0
0
BL1
BL0
RWEL
WEL
0
NV
NV
Bit(s)
CS7 - CS5
BL1 - BL0
RWEL
Description
Always “0”(RESERVED)
Sets the Block Lock partition
Register Write Enable Latch bit
WEL
Write Enable Latch bit
CS0
Always “0” (RESERVED)
NOTE: Bits labelled NV are nonvolatile (See “CONTROL AND STATUS REGISTER”).
Figure 17. CONSTAT Register Format
CONTROL AND STATUS REGISTER
The Control and Status (CONSTAT) Register provides the user with a mechanism for changing and
reading the status of various parameters of the
X9521 (See Figure 17).
The CONSTAT register is a combination of both volatile
and nonvolatile bits. The nonvolatile bits of the CONSTAT register retain their stored values even when Vcc
is powered down, then powered back up. The volatile
bits however, will always power-up to a known logic state
“0” (irrespective of their value at power-down).
A detailed description of the function of each of the CONSTAT register bits follows:
WEL: Write Enable Latch (Volatile)
The WEL bit controls the Write Enable status of the
entire X9521 device. This bit must first be enabled before
ANY write operation (to DCPs, EEPROM memory array,
or the CONSTAT register). If the WEL bit is not first
enabled, then ANY proceeding (volatile or nonvolatile)
write operation to DCPs, EEPROM array, as well as the
CONSTAT register, is aborted and no ACKNOWLEDGE
is issued after a Data Byte.
12
The WEL bit is a volatile latch that powers up in the disabled, LOW (0) state. The WEL bit is enabled / set by
writing 00000010 to the CONSTAT register. Once
enabled, the WEL bit remains set to “1” until either it is
reset to “0” (by writing 00000000 to the CONSTAT register) or until the X9521 powers down, and then up again.
Writes to the WEL bit do not cause an internal high voltage write cycle. Therefore, the device is ready for
another operation immediately after a STOP condition is
executed in the CONSTAT Write command sequence
(See Figure 18).
RWEL: Register Write Enable Latch (Volatile)
The RWEL bit controls the (CONSTAT) Register Write
Enable status of the X9521. Therefore, in order to write
to any of the bits of the CONSTAT Register (except
WEL), the RWEL bit must first be set to “1”. The RWEL
bit is a volatile bit that powers up in the disabled, LOW
(“0”) state.
It must be noted that the RWEL bit can only be set, once
the WEL bit has first been enabled (See "CONSTAT
Register Write Operation").
The RWEL bit will reset itself to the default “0” state, in
one of three cases:
—After a successful write operation to any bits of
the CONSTAT register has been completed (See
Figure 18).
—When the X9521 is powered down.
—When attempting to write to a Block Lock protected
region of the EEPROM memory (See "BL1, BL0: Block
Lock protection bits - (Nonvolatile)", below).
BL1, BL0: Block Lock protection bits - (Nonvolatile)
The Block Lock protection bits (BL1 and BL0) are
used to:
—Inhibit a write operation from being performed to certain addresses of the EEPROM memory array
—Inhibit a DCP write operation (changing the “wiper
position”).
FN8207.2
September 21, 2010
X9521
SCL
SDA
S
T
A
R
T
1
0
1
0
0
1
0
R/W A
C
K
1
1
1
1
1
1
ADDRESS BYTE
SLAVE ADDRESS BYTE
1
1
A
C
K
CS7 CS6 CS5 CS4 CS3 CS2 CS1 CS0
CONSTAT REGISTER DATA IN
A
C
K
S
T
O
P
Figure 18. CONSTAT Register Write Command Sequence
The region of EEPROM memory which is protected /
locked is determined by the combination of the BL1 and
BL0 bits written to the CONSTAT register. It is possible to
lock the regions of EEPROM memory shown in the table
below:
BL1 BL0
Protected Addresses
(Size)
Partition of array
locked
0
0
None (Default)
None (Default)
0
1
C0h - FFh (64 bytes)
Upper 1/4
1
0
80h - FFh (128 bytes)
Upper 1/2
1
1
00h - FFh (256 bytes)
All
If the user attempts to perform a write operation on a protected region of EEPROM memory, the operation is
aborted without changing any data in the array.
When the Block Lock bits of the CONSTAT register are
set to something other than BL1 = 0 and BL0 = 0, then
the “wiper position” of the DCPs cannot be changed - i.e.
DCP write operations cannot be conducted:
BL1
BL0
DCP Write Operation Permissible
0
0
YES (Default)
0
1
NO
1
0
NO
1
1
NO
The factory default setting for these bits are BL1 = 0,
BL0 = 0.
IMPORTANT NOTE: If the Write Protect (WP) pin of the
X9521 is active (HIGH), then all nonvolatile write operations to both the EEPROM memory and DCPs are inhibited, irrespective of the Block Lock bit settings (See "WP:
Write Protection Pin").
CONSTAT Register Write Operation
Only one data byte is allowed to be written for each
CONSTAT register Write operation. The user must issue
a STOP, after sending this byte to the register, to initiate
the nonvolatile cycle that stores the BP1and BP0 bits.
The X9521 will not ACKNOWLEDGE any data bytes
written after the first byte is entered (Refer to Figure 18.).
When writing to the CONSTAT register, the bits CS7CS5 and CS0 must all be set to “0”. Writing any other bit
sequence to bits CS7-CS5 and CS0 of the CONSTAT
register is reserved.
Prior to writing to the CONSTAT register, the WEL and
RWEL bits must be set using a two step process, with
the whole sequence requiring 3 steps
—Write a 02H to the CONSTAT Register to set the Write
Enable Latch (WEL). This is a volatile operation, so
there is no delay after the write. (Operation preceded
by a START and ended with a STOP).
—Write a 06H to the CONSTAT Register to set the Register Write Enable Latch (RWEL) AND the WEL bit.
This is also a volatile cycle. The zeros in the data byte
are required. (Operation preceded by a START and
ended with a STOP).
—Write a one byte value to the CONSTAT Register that
has all the bits set to the desired state. The CONSTAT
register can be represented as 000st010 in binary,
where st are the Block Lock Protection (BL1 and BL0)
bits. This operation is proceeded by a START and
ended with a STOP bit. Since this is a nonvolatile write
cycle, it will typically take 5ms to complete. The RWEL
bit is reset by this cycle and the sequence must be
repeated to change the nonvolatile bits again. If bit 2 is
set to ‘1’ in this third step (000s t110) then the RWEL
bit is set, but the BL1 and BL0 bits remain unchanged.
Writing a second byte to the control register is not
allowed. Doing so aborts the write operation and the
X9521 does not return an ACKNOWLEDGE.
The CONSTAT register is accessed using the Slave
Address set to 1010010 (Refer to Figure 4.). Following
the Slave Address Byte, access to the CONSTAT register requires an Address Byte which must be set to FFh.
13
FN8207.2
September 21, 2010
X9521
Signals from
the Master
WRITE Operation
S
t
a
r
t
SDA Bus
Slave
Address
S
t
Slave
a
r Address
t
Address
Byte
CS7 … CS0
S
t
o
p
10 1 0 0 1 01
10 1 0 0 1 0 0
A
C
K
Signals from
the Slave
READ Operation
A
C
K
A
C
K
Data
“Dummy” Write
Figure 19. CONSTAT Register Read Command Sequence
For example, a sequence of writes to the device CONSTAT register consisting of [02H, 06H, 02H] will reset the
BL0 and BL0 bits in the CONSTAT Register to “0”.
It should be noted that a write to any nonvolatile bit of
CONSTAT register will be ignored if the Write Protect
pin of the X9521 is active (HIGH) (See "WP: Write Protection Pin").
CONSTAT Register Read Operation
The contents of the CONSTAT Register can be read at
any time by performing a random read (See Figure 19).
Using the Slave Address Byte set to 10100101, and an
Address Byte of FFh. Only one byte is read by each register read operation. The X9521 resets itself after the first
byte is read. The master should supply a STOP condition
to be consistent with the bus protocol.
After setting the WEL and / or the RWEL bit(s) to a “1”,
a CONSTAT register read operation may occur, without
interrupting a proceeding CONSTAT register write
operation.
When reading the contents of the CONSTAT register,
the bits CS7 - CS5 and CS0 will always return “0”.
DATA PROTECTION
There are a number of levels of data protection features
designed into the X9521. Any write to the device first
requires setting of the WEL bit in the CONSTAT register.
A write to the CONSTAT register itself, further requires
the setting of the RWEL bit. Block Lock protection of the
device enables the user to inhibit writes to certain regions
of the EEPROM memory, as well as to all the DCPs. One
further level of data protection in the X9521, is incorporated in the form of the Write Protection pin.
WP: Write Protection Pin
When the Write Protection (WP) pin is active (HIGH), it
disables nonvolatile write operations to the X9521.
The table below (X9521 Write Permission Status) summarizes the effect of the WP pin (and Block Lock), on the
write permission status of the device.
Additional Data Protection Features
In addition to the preceding features, the X9521 also
incorporates the following data protection functionality:
—The proper clock count and data bit sequence is
required prior to the STOP bit in order to start a nonvolatile write cycle.
X9521 Write Permission Status
Block Lock
Bits
BL0
BL1
WP
DCP Volatile Write
Permitted
DCP Nonvolatile
Write Permitted
Write to EEPROM
Permitted
Write to CONSTAT Register
Permitted
Volatile Bits
Nonvolatile Bits
x
1
1
NO
NO
NO
NO
NO
1
x
1
NO
NO
NO
NO
NO
0
0
1
YES
NO
NO
NO
NO
x
1
0
NO
NO
Not in locked region
YES
YES
1
x
0
NO
NO
Not in locked region
YES
YES
0
0
0
YES
YES
Yes (All Array)
YES
YES
14
FN8207.2
September 21, 2010
X9521
ABSOLUTE MAXIMUM RATINGS
Parameter
Temperature under Bias
Storage Temperature
Voltage on WP pin (With respect to Vss)
Voltage on other pins (With respect to Vss)
| Voltage on RHx - Voltage on RLx | (x = 1,2. Referenced to Vss)
D.C. Output Current (SDA)
Lead Temperature (Soldering, 10 seconds)
Supply Voltage Limits (Applied Vcc voltage, referenced to Vss)
Min.
Max.
Units
-65
-65
-1.0
-1.0
2.7
+135
+150
+15
+7
Vcc
5
300
5.5
°C
°C
V
V
V
mA
°C
V
Min.
Max.
Units
-40
+85
°C
0
RECOMMENDED OPERATING CONDITIONS
Temperature
Industrial
NOTE: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This
is a stress rating only and the functional operation of the device at these or any other conditions above those listed in the
operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability
Figure 20. Equivalent A.C. Circuit
Vcc = 5V
2300Ω
SDA
100pF
Figure 21. DCP SPICE Macromodel
RTOTAL
RHx
CH
CL
RW
RLx
10pF
CW
10pF
25pF
(x = 1,2)
RWx
15
FN8207.2
September 21, 2010
X9521
TIMING DIAGRAMS
Figure 22. Bus Timing
tHIGH
tF
SCL
tLOW
tR
tSU:DAT
tSU:ST
SDA IN
tHD:DAT
tHD:STA
tSU:STO
tA
tDH
tBUF
SDA OUT
Figure 23. WP Pin Timing
START
SCL
Clk 1
Clk 9
SDA IN
tSU:WP
WP
tHD:WP
Figure 24. Write Cycle Timing
SCL
SDA
8th bit of last byte
ACK
tWC
Stop
Condition
16
Start
Condition
FN8207.2
September 21, 2010
X9521
Figure 25. DCP “Wiper Position” Timing
Rwx (x = 1,2)
Rwx(n + 1)
Rwx(n)
Rwx(n - 1)
twr
n = tap position
Time
SCL
SDA
S 1
T
A
R
T
0
1
0
1
1
1
SLAVE ADDRESS BYTE
17
0
A WT
C
K
0
0
0
0
0
INSTRUCTION BYTE
P1 P0
A
C
K
D7 D6 D5 D4 D3 D2 D1 D0
DATA BYTE
A
C
K
S
T
O
P
FN8207.2
September 21, 2010
X9521
D.C. OPERATING CHARACTERISTICS
Symbol
Parameter
Min
Typ
Max
Unit
Test Conditions / Notes
0.4
1.5
mA
fSCL = 400kHz
μA
VSDA = VCC
WP = Vss or Open/Floating
VSCL= VCC (when no bus activity
else fSCL = 400kHz)
10
μA
VIN (4) = GND to VCC.
10
μA
1
10
µA
0.1
10
μA
Current into VCC Pin
(X9521: Active)
Read memory array (3)
Write nonvolatile memory
ICC1(1)
Current into VCC Pin
(X9521:Standby)
With 2-Wire bus activity (3)
No 2-Wire bus activity
ICC2(2)
ILI
50
50
Input Leakage Current (SCL, SDA)
0.1
Input Leakage Current (WP)
Iai
Analog Input Leakage
ILO
Output Leakage Current (SDA)
VIL (6)
Input LOW Voltage (SCL, SDA, WP)
-0.5
0.8
V
VIH (6)
Input HIGH Voltage (SCL,SDA, WP)
2.0
VCC
+0.5
V
VOLx
SDA Output Low Voltage
0.4
V
VIN = VSS to VCC with all other
analog pins floating
VOUT (5) = GND to VCC.
X9521 is in Standby(2)
ISINK = 2.0mA
Notes: 1. The device enters the Active state after any START, and remains active until: 9 clock cycles later if the Device Select Bits in the Slave
Address Byte are incorrect; 200nS after a STOP ending a read operation; or tWC after a STOP ending a write operation.
Notes: 2.The device goes into Standby: 200nS after any STOP, except those that initiate a high voltage write cycle; tWC after a STOP that initiates
a high voltage cycle; or 9 clock cycles after any START that is not followed by the correct Device Select Bits in the Slave Address
Byte.
Notes: 3.Current through external pull up resistor not included.
Notes: 4.VIN = Voltage applied to input pin.
Notes: 5.VOUT = Voltage applied to output pin.
Notes: 6.VIL Min. and VIH Max. are for reference only and are not tested.
18
FN8207.2
September 21, 2010
X9521
A.C. CHARACTERISTICS (See Figure 22, Figure 23, Figure 24)
400kHz
Symbol
Parameter
Min
Max
Units
400
kHz
fSCL
SCL Clock Frequency
0
tIN (5)
Pulse width Suppression Time at inputs
50
tAA (5)
SCL LOW to SDA Data Out Valid
0.1
tBUF (5)
Time the bus free before start of new transmission
1.3
μs
tLOW
Clock LOW Time
1.3
μs
tHIGH
Clock HIGH Time
0.6
μs
tSU:STA
Start Condition Setup Time
0.6
μs
tHD:STA
Start Condition Hold Time
0.6
μs
tSU:DAT
Data In Setup Time
100
ns
tHD:DAT
Data In Hold Time
0
μs
tSU:STO
Stop Condition Setup Time
0.6
μs
Data Output Hold Time
50
ns
tDH
(5)
ns
μs
0.9
tR (5)
SDA and SCL Rise Time
20 +.1Cb (2)
300
ns
tF (5)
SDA and SCL Fall Time
20 +.1Cb (2)
300
ns
tSU:WP
WP Setup Time
0.6
μs
tHD:WP
WP Hold Time
0
μs
Cb
Capacitive load for each bus line
400
pF
A.C. TEST CONDITIONS
Input Pulse Levels
0.1VCC to 0.9VCC
Input Rise and Fall Times
10ns
Input and Output Timing Levels
0.5VCC
Output Load
See Figure 20
NONVOLATILE WRITE CYCLE TIMING
Symbol
tWC(4)
Parameter
Min.
Typ.(1)
Max.
Units
5
10
ms
Nonvolatile Write Cycle Time
CAPACITANCE (TA = 25°C, f = 1.0 MHz, VCC = 5V)
Symbol
Parameter
Max
Units
Test Conditions
COUT (5)
Output Capacitance (SDA, V1RO, V2RO, V3RO)
8
pF
VOUT = 0V
CIN (5)
Input Capacitance (SCL, WP)
6
pF
VIN = 0V
Notes: 1. Typical values are for TA = 25°C and VCC = 5.0V
Notes: 2.Cb = total capacitance of one bus line in pF.
Notes: 3.Over recommended operating conditions, unless otherwise specified
Notes: 4.tWC is the time from a valid STOP condition at the end of a write sequence to the end of the self-timed internal nonvolatile write cycle. It is
the minimum cycle time to be allowed for any nonvolatile write by the user, unless Acknowledge Polling is used.
Notes: 5.This parameter is not 100% tested.
19
FN8207.2
September 21, 2010
X9521
POTENTIOMETER CHARACTERISTICS
Limits
Symbol
Parameter
Max.
Units
-20
+20
%
RH Terminal Voltage (x = 1,2)
Vss
VCC
V
VRLx
RL Terminal Voltage (x = 1,2)
Vss
VCC
V
PR
Power Rating (1)(6)
10
mW
RTOTAL = 10kΩ (DCP1)
5
mW
RTOTAL = 100kΩ (DCP2)
200
400
Ω
IW = 1mA, VCC = 5 V,
VRHx = Vcc, VRLx = Vss
(x = 1,2).
400
1200
Ω
IW = 1mA, VCC = 2.7 V,
VRHx = Vcc, VRLx = Vss
(x = 1,2)
4.4
mA
RTOL
End to End Resistance Tolerance
VRHx
RW
IW
Min.
Typ.
DCP Wiper Resistance
Wiper Current (6)
Noise
Test Conditions/Notes
mV/
sqt(Hz)
RTOTAL = 10kΩ ( DCP1)
mV/
sqt(Hz)
RTOTAL = 100kΩ (DCP2)
Absolute Linearity (2)
-1
+1
MI(4)
Rw(n)(actual) - Rw(n)(expected)
Relative Linearity (3)
-1
+1
MI(4)
Rw(n + 1) - [Rw(n) + MI]
RTOTAL Temperature Coefficient
CH/CL/CW
Potentiometer Capacitances
twcr
Wiper Response time (6)
VTRIP
Vcc power-up DCP recall threshold
tPU
Vcc power-up DCP recall delay time (6)
±300
ppm/°C
RTOTAL = 10kΩ (DCP1)
±300
ppm/°C
RTOTAL = 100kΩ (DCP2)
pF
10/10/25
200
μs
See Figure 21.
See Figure 25.
V
25
50
75
ms
Notes: 1. Power Rating between the wiper terminal RWX(n) and the end terminals RHX or RLX - for ANY tap position n, (x = 1,2).
Notes: 2.Absolute Linearity is utilized to determine actual wiper resistance versus, expected resistance = (Rwx(n)(actual) - Rwx(n)(expected)) = ±1
Ml Maximum (x = 1,2).
Notes: 3.Relative Linearity is a measure of the error in step size between taps = RWx(n + 1) - [Rwx(n) + Ml] = ±1 Ml (x = 0,1,2)
Notes: 4.1 Ml = Minimum Increment = RTOT / (Number of taps in DCP - 1).
Notes: 5.Typical values are for TA = 25°C and nominal supply voltage.
Notes: 6.This parameter is periodically sampled and not 100% tested.
20
FN8207.2
September 21, 2010
X9521
APPENDIX 1
DCP1 (100 Tap) Tap position to Data Byte translation Table
Data Byte
Tap
Position
Decimal
Binary
0
0
0000 0000
1
1
0000 0001
.
.
.
.
.
.
23
23
0001 0111
24
24
0001 1000
25
56
0011 1000
26
55
0011 0111
.
.
.
.
.
.
48
33
0010 0001
49
32
0010 0000
50
64
0100 0000
51
65
0100 0001
.
.
.
.
.
.
73
87
0101 0111
74
88
0101 1000
75
120
0111 1000
76
119
0111 0111
.
.
.
.
.
.
98
97
0110 0001
99
96
0110 0000
21
FN8207.2
September 21, 2010
X9521
APPENDIX 2
DCP1 (100 Tap) tap position to Data Byte translation algorithm example. (Example 1)
unsigned
{
int
int
int
int
DCP1_TAP_Position(int tap_pos)
block;
i;
offset;
wcr_val;
offset= 0;
block = tap_pos / 25;
if (block < 0) return ((unsigned)0);
else if (block <= 3)
{
switch(block)
{
case (0): return ((unsigned)tap_pos) ;
case (1):
{
wcr_val = 56;
offset = tap_pos - 25;
for (i=0; i<= offset; i++) wcr_val-- ;
return ((unsigned)++wcr_val);
}
case (2):
{
wcr_val = 64;
offset = tap_pos - 50;
for (i=0; i<= offset; i++) wcr_val++ ;
return ((unsigned)--wcr_val);
}
case (3):
{
wcr_val = 120;
offset = tap_pos - 75;
for (i=0; i<= offset; i++) wcr_val-- ;
return ((unsigned)++wcr_val);
}
}
}
return((unsigned)01100000);
}
22
FN8207.2
September 21, 2010
X9521
APPENDIX 2
DCP1 (100 Tap) tap position to Data Byte translation algorithm example. (Example 2)
unsigned DCP100_TAP_Position(int tap_pos)
{
/* optional range checking
*/ if (tap_pos < 0) return ((unsigned)0);
else if (tap_pos >99) return ((unsigned) 96);
/* set to min val */
/* set to max val */
/* 100 Tap DCP encoding formula */
if (tap_pos > 74)
return ((unsigned) (195 - tap_pos));
else if (tap_pos > 49)
return ((unsigned) (14 + tap_pos));
else if (tap_pos > 24)
return ((unsigned) (81 - tap_pos));
else return (tap_pos);
}
23
FN8207.2
September 21, 2010
X9521
20-LEAD PLASTIC, TSSOP PACKAGE TYPE V
.025 (.65) BSC
.169 (4.3)
.252 (6.4) BSC
.177 (4.5)
.252 (6.4)
.260 (6.6)
.047 (1.20)
.0075 (.19)
.0118 (.30)
.002 (.05)
.006 (.15)
(4.16)
.010 (.25)
(7.72)
Gage Plane
0° - 8 °
Seating Plane
.019 (.50)
.029 (.75)
(1.78)
(0.42)
Detail A (20X)
(0.65)
ALL MEASUREMENTS ARE TYPICAL
.031 (.80)
.041 (1.05)
See Detail “A”
NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS)
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
24
FN8207.2
September 21, 2010
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