SHARP_LH7A404 Datasheet, PDF (29/51 Pages) Sharp Electrionic Components – 32 BIT SYSTEM ON CHIP

32-Bit System-on-Chip
LH7A404
Keyboard and Mouse Interface (KMI)
The Keyboard and Mouse Interface has the follow-
ing features:
• IBM PS2 or AT-compatible keyboard or mouse inter-
face
• Half-duplex bidirectional synchronous serial inter-
face using open-drain outputs for clock and data.
• Programmable 4-bit reference clock divider
• Polled or interrupt-driven mode
• Separately maskable transmit and receive interrupts
• Single combined interrupt output
• Odd parity generation and checking
• Register bits for override of keyboard clock and data
lines.
Additional test registers and modes are implemented
for functional verification and manufacturing test.
Touch Screen Controller (TSC)
The Touch Screen Controller is a complete interface
to a touch screen as used in portable personal devices.
It combines the front-end biasing and control circuitry
with analog-to-digital conversion, reference genera-
tion, and digital control and interface functions to com-
pletely replace external ICs used to implement this
interface. The features are:
• 10-bit A/D converter with integrated sample-and-
hold, fully differential, high impedance signal and ref-
erence inputs.
• Input active matrix for bias and control circuits nec-
essary for connection to external 4- and 5-wire touch
sensitive panels.
• Auxiliary functions such as temperature sense, pen
pressure sense, battery voltage sense, in addition to
normal direct voltage inputs.
• A 10-channel multiplexer for routing user-selected
inputs to A/D
• 16 × 16 FIFO for 10-bit digital output of A/D
• Pen down sensor to generate interrupts to the host
• Low power circuitry and power control modes to min-
imize in-system power dissapation.
• Conversion automation to maximize flexibility while
minimizing CPU management and interrupt overhead
• Supply voltage 3.0 V - 3.6 V
• Configurable input pads so that when an Analog input
is not being used, the pad can be used as a GPIO.
Battery Monitor Interface (BMI)
The BMI is a serial communication interface speci-
fied for two types of battery monitors/gas gauges. The
first type employs a single wire interface. The second
interface employs a two-wire multi-master bus, the
Smart Battery System Specification. If both interfaces
are enabled at the same time, the Single Wire Interface
will have priority.
SINGLE WIRE INTERFACE
The Single Wire Interface performs:
• Serial-to-parallel conversion on data received from
the peripheral device
• Parallel-to-serial conversion on data transmitted to
the peripheral device
• Data packet coding/decoding on data transfers
(incorporating Start/Data/Stop data packets)
The Single Wire interface uses a command-based
protocol in which the host initiates a data transfer by
sending a WriteData/Command word to the battery
monitor. This word always contains the command sec-
tion, which tells the Single Wire Interface device the
location for the current transaction. The most signifi-
cant bit of the command determines if the transaction is
Read or Write. In the case of a Write transaction the
word will also contain a WriteData section with the data
to be written to the peripheral.
SMART BATTERY INTERFACE
The Smart Battery Interface performs:
• Serial-to-parallel conversion on data received from
the peripheral device
• Parallel-to-serial conversion of data transmitted to
the peripheral device.
The Smart Battery Interface uses a two-wire multi-
master bus (the SMBus), allowing multiple bus masters
to be connected to it. A master device initiates a bus
transfer and provides the clock signals. A slave device
can receive data provided by the master or it can provide
data to the master. Since more than one device may
attempt to take control of the bus as a master, SMBus
provides an arbitration mechanism by relying on the
wired-AND connection of all SMBus interfaces to the
SMBus.
Advance Data Sheet
29