Chapter 5 — Firmware Download
58 ED40 Decode Board Integration Guide
RTS/CTS Hardware Protocol
RTS/CTS hardware protocol is active by default in the imager. However, the
imager is always ready to receive a character from the host on its RXD line so the
host does not need to use a hardware protocol to send data to the imager. RTS/
CTS hardware protocol uses four lines as indicated below:
The imager:
• requests permission from the host each time it wants to transmit a byte
• receives permission from the host
• transmits a byte
• removes the request after transmission of the byte
• waits for the host to remove permission before making another request
The host:
• grants permission when the imager requests to transmit a byte
• awaits reception of the byte
• removes permission after receiving the byte
Host Signals Imager Signals Description
RXD (input) TXD (output) Imager transmits data to the host.
TXD (output) RXD (input) Host transmits data to the imager.
CTS (input) RTS (output) Imager asks the host for permission to
transmit a character.
RTS (output) CTS (input) Host authorizes the imager to transmit a
character.
HOST SCAN ENGINE
RXD
RXD
TXD
TXD
CTS
CTS
RTS
RTS
To Next Page
Loading...