Sc3200 Super I/O - Micros Systems Workstation 4 LX Service Manual

SC3200 Super I/O

REF: AB28/ABRD36 - Sheets 1 and 2
The SC3200 Super IO module comprises a collection of 8 functional blocks, host
interface, and a central configuration register set, all attached to the internal 8-bit data
bus.
The host interface serves a bridge between the external ISA bus and the internal bus
and supports 8-bit IO read, 8-bit IO write and 8-bit DMA transactions. The remaining
functional blocks are briefly described below.
Parallel Port
The SC3200 Super IO parallel port includes an IEEE 1284 compatible parallel
port interface. However, the SC3200 parallel port interface is not implemented.
ACCESS.bus (ACB) Interface
The ACB is a two-wire synchronous serial interface compatible with the
ACESS.bus physical layer. The ACB is also compatible with the Intel SMBus
(System Management Bus) and Phillips I
bi-directional Serial Data Line (SDL), and Serial Clock Line (SCL) which allows
easy interfacing to a wide range of memories and IO devices, including
EEPROMs, SDRAMs, timers, ADCs, DAC, clock chips and peripheral devices.
As shown in the block diagram, ACB2 is not used. However, ACB1 is connected
to socket DIMM1 and is implemented as a Serial Presence Detect (SPD) Interface
to the DIMM. The Boot Loader utilizes DRAM timing parameters stored in the
EEPROM to optimize the SC3200 memory controller.
Serial Interface
The SC3200 block diagram in Figure 2-4 shows three serial ports, labeled
UART1, UART2, and UART3. Each UART contains the equivalent of a 16550
UART with 16 byte FIFO buffer.
UART1 is assigned to the touchscreen interface located on COM2. The interface
is a simple two-wire TX/RX interface and is connected to touchscreen controller
U38 without the use of RS232 level converters.
UART2 is assigned to the rear panel DB9 connector designated as COM1.
Handshake signals required for this interface are supplied by General Purpose IO
pins on the SC3200. These pins are shared with IDE control signals.
UART3 is assigned to COM5 and dedicated to RS422 Port B. The control signals
required to manage the RS422/RS232 selection and TX enable for this port are
supplied from GPIO ports on Super IO chip, U15.
Real Time Clock (RTC)
The RTC provides timekeeping and calendar management functions. It also
includes 242 bytes of battery backed RAM for general-purpose use.
Workstation 4 and 4 LX Field Service Guide
WS4 Technical Overview

SC3200 Super I/O

2
C bus. The interface is composed of a
2-11