Switching Between Mcu And Mpu Modes; Installing An Rs232C Interface; Mounting A Key Input Emulator Port; List Of Recommended Parts - Epson S5U1C88348T Manual

4.4 Switching between MCU and MPU Modes

The S5U1C88348T's MCU/MPU pin is user-configurable to permit running it in MPU mode after replac-
ing its MPU board with another CPU (S1C88348/317/316/308). When shipped from the factory, this pin
is set to MCU mode by a wiring pattern.
To use the S5U1C88348T in MPU mode, perform the following steps.
(1) Cut the pattern connecting JP4 pins 1 and 2 and attach a jumper pin to JP4.
(2) Set up the JP4 jumper socket as shown in the following table.
Note: The S1C8P348 is set to MCU mode and cannot be switched to MPU mode. When using the MPU
board of the S1C8P348 after modifying jumpers, the JP4 jumper socket must be set to 1–2.

4.5 Installing an RS232C Interface

An RS232C port may be installed in the S5U1C88348T to communicate with a PC or other device. When
using an RS232C port, mount a D-SUB 9-pin connector on the Main Board's CN16 pattern, a driver IC
(MAXIM MAX232CPE) on the U7 pattern and capacitors C20 to C24. Furthermore, connect between pin
16 of U8 and pin 16 of U7 using a jumper wire. Since the MAX232CPE is designed to operate with 5 V, it
must be removed when using the S5U1C88348T in battery mode. For this reason, we recommend using
an IC socket.
Serial input/output operations are controlled by setting the S1C8P348's internal serial interface to
asynchronous mode. Although the SCLK pin can be used as a general-purpose port (P12), note that this
signal is also connected to D-SUB connector pin 8. It can be used as a CTS signal.

4.6 Mounting a Key Input Emulator Port

The S5U1C88348T can support key input emulation by data transmitted from a PC. To implement this
function, create a key input emulator board to reproduce key states from LPT output of a PC and connect
it to the S5U1C88348T. When using an input emulator, mount a 20-pin connector on the CN15 pattern and
use it to attach the emulator.
Before creating a key input emulator, see the circuit diagram "Key Emulation Circuit for 88S5U1C88348T"
located at the end of this manual.

4.7 List of Recommended Parts

The table below lists the parts need to modify S5U1C88348T functions. We recommend using the follow-
ing products or their equivalent.
Item
Jumper pin
Jumper socket
ROM
RAM
RS232C driver
RS232C connector
Key emulate connector
S5U1C88348T HARDWARE MANUAL
Table 4.4.1 JP4 Settings
CPU mode
MCU
MPU
Table 4.7.1 List of Recommended Parts
Part name
PS-3PF-S4T1-PKL1
PS-2SH4-1
64K bytes (512 bits)
TMS27C512-10JL
32K bytes (256 bits)
HM62256BLP-10SL
MAX232CPE
D-SUB connector
DELC-J9PAF-13L8
PS-20PE-D4T1-B1
EPSON
4 CHANGING SETTINGS AND MOUNTING PARTS
JP4
1–2
2–3
Manufacturer
JAE
JAE
TI Operates with 5 V. Check power supply
voltage in battery mode.
Hitachi
MAXIM Operates with 5 V.
Remove the IC in battery mode.
JAE
JAE
Remark
II-9