SMS66
Preliminary Information
enable by writing other codes (not 0101BIN) to the write
protection register. Writing to the write protection
register is shown in Figure 7.
CONFIGURATION REGISTERS
The majority of the configuration registers are grouped
with the general-purpose memory located at either
slave address 1010BIN or 1011BIN. The bus address
bits, A[1:0], used to differentiate the general-purpose
memory from the configuration registers are set to
11BIN. Bus address bit A[2] can be programmed as
either 0 or biased by the A2 pin.
COMMAND AND STATUS REGISTERS
The command and status registers are located at
slave address 1001BIN
.
Writes and reads of the
command and status registers are shown in Figures
16 and 17.
ADC CONVERSIONS
An ADC conversion on any monitored channel can be
performed and read over the I2C bus using the ADC
read command. The ADC read command, shown in
Figure 18, starts with a dummy write to the 1001BIN
slave address. Bits [6:3] of the word address byte are
used to address the desired monitored input. Once
the device acknowledges the channel address, it
begins the ADC conversion of the addressed input.
This conversion requires 70µs to complete. During
this conversion time, acknowledge polling can be
used. The SMS66 will not acknowledge the address
bytes until the conversion is complete. When the
conversion has completed, the SMS66 will
acknowledge the address byte and return the 10-bit
conversion along with the 4-bit channel address echo.
Two additional configuration registers are located at
addresses 83HEX and 84HEX of slave address 1001BIN
.
Writing and reading the configuration registers is
shown in Figures 8, 9, 10,11 and 12.
GENERAL-PURPOSE MEMORY
The 4k-bit general-purpose memory is located at
either slave address 1010BIN or 1011BIN
.
The bus
address bits, A[1:0], used to differentiate the general-
purpose memory from the configuration registers are
set to 00BIN for the first 2k-bits and 01BIN for the second
2k-bits. Bus address bit A[2] can be programmed as
either 0 or biased by the A2 pin. The word address
must be set each time the memory is accessed.
Memory writes and reads are shown in Figures 13, 14
and 15.
GRAPHICAL USER INTERFACE (GUI)
Device configuration utilizing the Windows based
SMS66 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 and Application
Note 33, simplifies the process of device prototyping
and the interaction of the various functional blocks. A
programming Dongle (SMX3200) is available from
Summit to communicate with the SMS66. The Dongle
connects directly to the parallel port of a PC and
programs the device through a cable using the I2C bus
protocol.
Slave Address Bus Address Register Type
Write Protection Register,
Command and Status Registers,
Two Configuration Registers,
ADC Conversion Readout
1001BIN
A2 A1 A0
A2 0 0
A2 0 1
A2 1 1
1st 2-k Bits of General-Purpose Memory
2nd 2-k Bits of General-Purpose Memory
Configuration Registers
1010BIN
or
1011BIN
Table 1 - Address bytes used by the SMS66.
Summit Microelectronics, Inc
2070 1.0 7/16/03
19
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
