Rio3-Rs232 (1Ch) Rxd Buffer Data Overrun Check - Hitachi HX-RIO3 Series User Manual

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4.2.5 RIO3-RS232 (1ch) RxD Buffer data Overrun Check

For example, if other device transmits 1025 bytes of TxD data, RxD buffer of RIO3-RSxx (Serial) will be
overwritten 1 bytes.
Other device
Offset
Output Byte #1
Output Byte #2
Output Byte #3
Output Byte #4
Output Byte #5
Output Byte #6
.
.
.
Output Byte #1020
Output Byte #1021
Output Byte #1022
Output Byte #1023
Output Byte #1024 MAX
Output Byte #1025
RE (RxD Exist) bit check
bit#7
TPA
Status Byte
#0
RA (Receive Acknowledge) bit set
bit#7
Control Byte TPR
#0
PLEASE CHECK RBO bit in Status Byte in order to prevent overwrite RX buffer.
When the RBO bit is set, it notifies that the RX buffer is full.
Status Byte #0
TxD Data
0x01
0x02
0x03
0x04
0x05
0x06
.
.
.
0x01
0x02
0x03
0x04
0x05
0x06(Overrun data)
bit#6 bit#5
FTA FRA
0 0 0
bit#6 bit#5
FT FR
0 0 0
bit#7 bit#6 bit#5
TPA FTA FRA
0 0
Offset
Input Byte #1
Input Byte #2
Input Byte #3
Input Byte #4
Input Byte #5
Input Byte #6
.
.
.
Input Byte #1019
Input Byte #1020
Input Byte #1021
Input Byte #1022
Input Byte #1023
Input Byte #1024
bit#4 bit#3
RE RBO
1 0
bit#4 bit#3
---- ----
0 0
bit#4 bit#3
RE RBO
0 1 1
HX-RIO3 Series
RIO3-RSxx (Serial)
RxD Buffer data
0x06(Overrun data)
0x02
0x03
0x04
0x05
0x06
0x10
0x01
0x02
0x03
0x04
0x05
bit#2 bit#1
RR TA
0 0
bit#2 bit#1
RA TR
1 0
bit#2 bit#1
RR TA
1 0
bit#0
IA
0
bit#0
IR
0
bit#0
IA
0