DS4510 Maxim, DS4510 Datasheet - Page 9

• Manufacturer Part Number: DS4510
• Description: The DS4510 is a CPU supervisor with integrated 64-byte EEPROM memory and four programmable, nonvolatile (NV) I/O pins
• Manufacturer: Maxim

time (see
during a bit read. The device shifts out each bit of data
on SDA at the falling edge of the previous SCL pulse
and the data bit is valid at the rising edge of the current
SCL pulse. Remember that the master generates all
SCL clock pulses, including when it is reading bits from
the slave.
Acknowledgement
Acknowledgement (ACK) or Not Acknowledge (NACK)
is always the 9th bit transmitted during a byte transfer.
The device receiving data (the master during a read or
the slave during a write operation) performs an ACK by
transmitting a zero during the 9th bit. A device per-
forms a NACK by transmitting a one during the 9th bit.
Timing
all other bit writes. An ACK is the acknowledgment that
the device is properly receiving data. A NACK is used
to terminate a read sequence or as an indication that
the device is not receiving data.
Byte Write: A byte write consists of 8 bits of informa-
tion transferred from the master to the slave (most sig-
nificant bit first) plus a 1-bit acknowledgement from the
Table
LOCATION (HEX)
REGISTER
CPU Supervisor with Nonvolatile Memory and
FA to FF
00 to 3F
40 to EF
F2 to F3
F4 to F7
(Figure
1. Register Definitions
F0
F1
F8
F9
Figure
5) for the ACK and NACK is identical to
5) before the next rising edge of SCL
User EEPROM
Reserved
Pullup Enable
RST Delay
User SEEPROM
I/O
I/O Status
Config
Bit Name
ready
Trip Point
Reset Status
SEE
SWRST
User SRAM
REGISTER
X
Control
NAME
(ACK
and
64 bytes of EEPROM memory.
These memory locations are reserved for future products.
The four least significant bits of this register each enable/disable one of the internal pullup
resistors. Set the bit to enable the pullup, clear it to disable the pullup.
The two LSBs of this register (TD1 and TD0) select the reset delay (t
CPU Supervisor AC Timing Characteristics.
SRAM Shadowed EEPROM user byte.
Clearing the LSB of the register enables the I/O
the pulldown transistor.
This register reflects the logic level of the I/O
always read zero.
This register contains 5 bits that read and control the behavior of the part as follows:
Bit Function
Reads zero when V
Reads one when V
Reads one when the RST pin is active.
When zero, writes to the SEEPROM registers behave like EEPROM. When one, writes to the
SEEPROM registers behave like SRAM.
Setting this bit activates the RST output. This bit automatically returns to zero during the
RST active time.
6 bytes of SRAM memory
_____________________________________________________________________
NACK):
CC
CC
An
below V
is above the DS4510's power-on reset voltage.
slave to the master. The 8 bits transmitted by the mas-
ter are done according to the bit-write definition and the
acknowledgement is read using the bit-read definition.
Byte Read: A byte read is an 8-bit information transfer
from the slave to the master plus a 1-bit ACK or NACK
from the master to the slave. The 8 bits of information
that are transferred (most significant bit first) from the
slave to the master are read by the master using the
bit-read definition above, and the master transmits an
ACK using the bit-write definition to receive additional
data bytes. The master must NACK the last byte read
to terminate communication so the slave will return con-
trol of SDA to the master.
Slave Address and the
bus responds to a slave addressing byte sent immedi-
ately following a start condition. The slave address byte
contains the slave address and the R/W bit. The slave
address (see
the R/W bit is the least significant bit.
The DS4510’s slave address is 101000A
where A
CCTP
.
0
FUNCTION
is the value of the A
Programmable I/O
X
Figure
pins. The upper four bits of this register
X
pulldown transistor; setting the bit disables
6) is the most significant 7 bits and
R/W Bit: Each slave on the I
RST
0
address pin. The
) as shown in the
0
(binary),
2
C
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