Renesas R5S72623 User Manual

 

Section 21   IEBus

TM

 Controller 

R01UH0134EJ0400  Rev. 4.00  

 

Page 1149 of 2108 

Sep 24, 2014 

 

 

 
SH7262 Group, SH7264 Group 

When the maximum number of bytes defined by the communications mode have been transmitted 
because a NAK has been received from the receive unit or transmission has not been completed 
because the message length value exceeds the maximum number of transfer bytes in one frame, 
this module sets the error flag and enters a wait state. At this time, transfer proceeds until the (n + 
1)th byte has been transmitted, where n is the maximum number of transfer bytes. Then, when 
NAK is received via the acknowledge bit of the (n + 1)th byte, the TXERO flag is set. If ACK is 
received rather than NAK, the TXF flag is set. 

Figure 21.18 shows the timing of operations when the maximum number of transfer bytes is 
reached but transmission has not been completed. 

[Legend]

HD: Header 
MA:  Master address field 
SA: 

Slave address field 

CT: Control 

field 

DL: 

Message length field 

Dn: 

Data field (n = Maximum number of transfer bytes)

Master 

transmission

IETSR

TXERO

TXF

Dn+1

Dn-1

Dn

HD

MA

SA

CT

DL

D1

D2

When ACK is received for Dn + 1

When NAK is received for Dn + 1