SMB139 SUMMIT Microelectronics, Inc:, SMB139 Datasheet - Page 17

• Manufacturer Part Number: SMB139
• Description: ? Summit Microelectronics, Inc. 2005 ? 757 N. Mary Avenue ? Sunnyvale Ca 94085 ? Phone [phone] ? Fax [phone] Http //www.summitmicro.com/ 2121 3.0 6/19/2008 1 Programmable Linear Battery Charger
• Manufacturer: SUMMIT Microelectronics, Inc:

SERIAL INTERFACE
Access to the configuration registers, command and
status registers is carried out over an industry
standard 2-wire serial interface (I
directional data line and SCL is a clock input (Figure4).
Data is clocked in on the rising edge of SCL and
clocked out on the falling edge of SCL.
transfers begin with the MSB. During data transfers,
SDA must remain stable while SCL is high. Data is
transferred in 8-bit packets with an intervening clock
period in which an Acknowledge is provided by the
device receiving data. The SCL high period (t
used for generating Start and Stop conditions that
precede and end most transactions on the serial bus.
A high-to-low transition of SDA while SCL is high is
considered a Start condition while a low-to-high
transition of SDA while SCL is high is considered a
Stop condition.
The interface protocol allows operation of multiple
devices and types of devices on a single bus through
unique device addressing.
comprised of a 7-bit device type identifier (slave
address). The remaining bit indicates either a read or
a write operation. Refer to Table 1 for a description of
the address bytes used by the SMB139.
The device type identifier for the configuration
registers and the command and status registers are
accessible with the same slave address. The slave
address can be can be programmed to any seven bit
number 0000000
WRITE
Writing to a configuration register is illustrated in
Figures 10 and 11. A Start condition followed by the
slave address byte is provided by the host; the
SMB139 responds with an Acknowledge; the host then
responds by sending the memory address pointer or
configuration register address pointer; the SMB139
responds with an acknowledge; the host then clocks in
one byte of data. For configuration register writes, up
to 15 additional bytes of data can be clocked in by the
host to write to consecutive addresses within the same
page.
Summit Microelectronics, Inc
I
2
C PROGRAMMING INFORMATION
BIN
through 1111111
Slave Address
ANY
The address byte is
Table 3 – Address bytes used by the SMB139.
2
C). SDA is a bi-
BIN
. Table 3.
Register Type
Configuration Registers are located in 00
05
All data
HEX
HIGH
2121 3.0 6/19/2008
, 08
) is
HEX
and 0F
After the last byte is clocked in and the host receives
an Acknowledge, a Stop condition must be issued to
initiate the nonvolatile write operation.
READ
The address pointer for the non-volatile configuration
registers and memory registers as well as the volatile
command and status registers must be set before data
can be read from the SMB139. This is accomplished
by issuing a dummy write command, which is a write
command that is not followed by a Stop condition. A
dummy write command sets the address from which
data is read.
issued, a Start command followed by the address byte
is sent from the host.
Acknowledge and then begins clocking data out of the
slave device.
address pointer set during the dummy write command.
Additional bytes can be clocked out of consecutive
addresses with the host providing an Acknowledge
after each byte. After the data is read from the desired
registers, the read operation is terminated by the host
holding SDA high during the Acknowledge clock cycle
and then issuing a Stop condition. Refer to Figure 12
for an illustration of the read sequence.
CONFIGURATION REGISTERS
Writing and reading the configuration registers is
shown in Figures 10, 11 and 12. A description of the
configuration registers is shown in Table 4 through
Table 15.
GRAPHICAL USER INTERFACE (GUI)
Device configuration utilizing the Windows based
SMB139 graphical user interface (GUI) is highly
recommended. The software is available from the
Summit website (www.summitmicro.com). Using the
GUI in conjunction with this datasheet, simplifies the
process of device prototyping and the interaction of
the various functional blocks. A programming Dongle
(SMX3202) is available from Summit to communicate
with the SMB139. The Dongle connects directly to the
USB port of a PC and programs the device through a
cable using the I
SMX3202 Data Sheet.
HEX
The first byte read is data from the
After the dummy write command is
2
C bus protocol. See Figure 9 and the
HEX
The host then waits for an
thru
SMB139
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