Sharp PC-G850VS,PC-G850V User Manual/ Interface

SHARP&PC-G850V(S)&&&Manual&

SHARP

POCKET COMPUTER

MODEL

PC-G850V(S)

User Manual/ Interface

SHARP&PC-G850V(S)&&&User&Manual&-&&Appendix!A:!11-Pin!Interface&

Version 1.1, 12/2016

! &

SHARP&PC-G850V(S)&&User&Manual&-&Appendix!A:!11-Pin!Interface&

Appendix&A:&11-Pin&Interface&

Signals&and&Pin-Out&

On the left side of the PC-G850V(S) there is an 11-pin interface intended for communication with other devices. It is a multi-functional interface, hence it can operate in different (sub-)modes. The actual mode is selected through operational commands or menue items of the PC-G850V(S).

1. SIO / RS-232C-mode (e.g. OPEN“COM:“)

2. SSIO-mode (Synchronous Serial Input/Output) a. CE-126P print protocol (e.g. LPRINT without preceding OPEN)

b. LPRT-protocol (e.g. OPEN“LPRT:“)

3. PWM-mode (Pulse Width Modulation) a. CE-126P tape protocol (e.g. BSAVE/BLOAD with a CE-126P) b. Generic PWM-protocol (e.g. BSAVE/BLOAD with another PC-G850V)

4. PIO-mode (e.g. OPEN“PIO:“)

Programmable, 8-bit parallel port interface

5. PIC-mode (activated by the PIC-loader in the assembler menue)

Programming interface for PIC microcontrollers

The association of physical pins to logical signals (called pin-out) as well as the configured direction for input (I) or output (O) depends on the active mode. The following table gives an overview. Looking from the left side of the PC-G850V(S) pin-1 is the leftmost and pin-11 the rightmost.

Pin #

SIO-Mode

SSIO/PWM-Mode

PIO-Mode

PIC-Mode

Signal

I/O

Signal

I/O

Signal

I/O

Signal

I/O 1 - - - - - - -

VCC(+5V)

GND

RTS

BUSY

Bit0

I/O

DTR

DOUT

Bit1

I/O

CLK#

RXD

XIN

Bit2

I/O

DATAIN

TXD

XOUT

Bit3

I/O

DATAOUT

O 8 CD

DIN

Bit4

I/O

LOWBATT#

CTS

ACK

Bit5

I/O - -

DSR

EX1

Bit6

I/O - -

CI I EX2

Bit7

I/O - -

The next sections describe the SIO-mode and respective connection options in detail. The other modes are covered subsequently.

SHARP&PC-G850V(S)&&&User&Manual&-&&Appendix!A:!11-Pin!Interface&

SIO-Mode:&RS-232&Standard&and&Conventions&

The PC-G850V(S) in SIO-mode exposes the signals of the RS-232 standard, but with different voltage levels (see below). This section provides the necessary basics of the standard and covers some specifics of the PC-G850V(S).

Within the RS-232 standard the terms DTE (Data Terminal Equipment) and DCE (Data Communication Equipment) are introduced. The DTE is the PC-G850 for example and the DCE is a modem or another peripheral device, like a serial printer.

When two computers shall communicate directly (i.e. without a modem), you need a so called null-modem (cable/adaptor), which connects the outputs of one DTE with the inputs of the other and vice versa (crossed signals).

Typically 25-pin (Sub-D 25 / DB-25) or 9-pin (Sub-D 9 / DB-9) plugs and jacks are used to connect RS-232 capable devices.

SHARP&PC-G850V(S)&&User&Manual&-&Appendix!A:!11-Pin!Interface&

The pin-out and meanings are summarized in the following table.

Signal

Name

Alternative Name

Direction (DTEView)

Semantics

Pin# DB-9

Pin# DB-25 TXD

Transmitted Data

Out

Data from DTE to DCE

3 2 RXD

Received Data

Data from DCE to DTE

RTS

Request To Send (Ready To Send)

Out

DTE requests permission from DCE to send data

RTR

Ready To Receive

DTE is ready to receive data from DCE

CTS

Clear To Send

DCE is ready to receive data from DTE

8 5 DTR

Data Terminal Ready

Out

DTE interface ready for operation

DSR

Data Set Ready

DCE interface ready for operation

6 6 CD

Carrier Detect

DCE detects remote DCE (e.g. telephone line)

8 CI

Call Indicator

Call of a remote DCE

GND

Signal Ground

None

Signal-ground (reference)

5 7 FG

Frame Ground

None

Shield

Remark: In the late 1980’s there was a shift in the meaning of the RTS-signal: Originally the DTE (computer) requests the DCE (modem) for permission that the DTE may send data - and the DCE “answeres” via CTS. But this protocol is asymmetric because the DTE has no means to notify the DCE to wait for internal computations when the DCE sends data. For this reason “Request To Send” was re-claimed: The DTE requests the DCE to send data – or in other words, the DTE is “Ready To Receive” (RTR). RTR and CTS are now independent of each other and the protocol between DTE and DCE is symmetric. But in most cases the name “Request To Send” (RTS) was kept, hence it is fairly ambiguous.

The PC-G850V(S) implements the newer, symmetric RTR-semantics (but the signal name RTS has been kept). This is in contrast to the preceding pocket computer model PC-E500(S), which implements the original RTS meaning and therefor needs the XON/XOFF-protocol in addition, when it reads data/programs from a PC. The PCG850V(S) sets the DTR-signal to HIGH, when the SIO-interface is active, but it does not care about the DSR-input. So there is no DTR/DSR-handshake. The RTS/CTShandshake, or alternatively the XON/XOFF-protocol can be configured in the TEXT/Sio/Format-submenue by the item "flow".

SHARP&PC-G850V(S)&&&User&Manual&-&&Appendix!A:!11-Pin!Interface&

SIO-Mode:&Signal&Levels&

The next table summarizes the logic- and voltage-levels of the RS-232 standard in comparison with UART-TTL and the PC-G850V(S).

Logic level

Voltage level

Semantics for data signals (RXD,TXD)

Semantics for control signals (RTS,CTS,etc.)

RS-232 LOW

-15V to -3V

1 (Mark), Idle, Stop

Inactive

HIGH

+3V to +15V

0 (Space), Start

Active

UART-TTL LOW

0 (Space), Start

Active

HIGH

+3,3V / +5V

1 (Mark), Idle, Stop

Inactive

PC-G850V(S) LOW

1 (Mark), Idle, Stop

Inactive

HIGH

0 (Space), Start

Active

So the PC-G850V(S) exposes inverted UART-TTL level signals in SIO-mode, just as most other SHARP pocket computers do. That means the logic is identical to the RS-232 standard (HIGH=0/active), but the voltage level is TTL.

ð In order to connect peripheral devices with the PC-G850V(S) that operate at

RS-232 voltage levels, a level converter is mandatory!

The state of the TXD- and RTS-signals in SIO-mode is undefined, except for the following cases:

1. The interface has explicitly been opened in SIO-mode (e.g. OPEN“COM:“) when in

operational main mode “BASIC”.

2. R- or W-commands are executed in operational main mode “Monitor”.

3. Data transfer via SIO in operational main mode “TEXT”.

SHARP&PC-G850V(S)&&User&Manual&-&Appendix!A:!11-Pin!Interface&

SIO-Mode:&Data&Transfer&Cable&CE-T800&and&CE-T801&

The data transfer cables CE-T800 and CE-T801 are RS-232 level converters with an integrated null-modem wiring. They can be used to connect the PC-G850V(S) to a personal computer (PC) or other devices.

With these cables you can transfer data, program source-code or machine language programs from or to a PC by using the TEXT/Sio-submenue or the SIO-commands (R, W) of the integrated hex-monitor (MON). The DB-25 plug of the cable can be connected directly to a PC (if necessary via a DB-9 adaptor), when there is a physical COM port. Alternatively it can be connected to a USB-port through an additional serial-to-USB adaptor. Don't use a null-modem adaptor or wiring for a PC-connection (because it's already integrated in the cable).

However if a peripheral RS-232 device like the 4-color plotter CE-515P shall be connected, a null-modem adaptor/wiring is mandatory in order to compensate the integrated one.

On the CE-T800 pins 6 and 20 are not connected, pin 11 is not connected on both models (CE-T800 and CE-T801).

Attention: Never touch the pins of the DB-25 plug. Static electricity may be harmful for the circuits.

A free working area of about 300bytes is required for data transfer from a PC.

+ 15 hidden pages

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