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Section 21 IEBus
TM
Controller
Page 1150 of 2108 R01UH0134EJ0400 Rev. 4.00
Sep 24, 2014
SH7262 Group, SH7264 Group
(2) Data Reception
When the data reception has not finished within the maximum number of bytes defined by the
communications mode because of a parity error or overrun error causing the retransfer of data, or
reception 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 state of waiting for the
(n + 1)th byte of data, where n is the maximum number of transfer bytes. Thus, when data of the
(n + 1)th byte cannot be received, the receive timing error is detected and the RXERTME flag is
set. At this time, the RXEDLE flag is not set. The RXEDLE flag is set when the (n + 1)th byte is
received.
In the same way, when the maximum number of transfer bytes has been received and a parity error
has not been cleared, and the (n + 1)th byte cannot be received, the RXERTME flag is set. At this
time, the RXEPE flag is not set. The RXEPE flag is set when the (n + 1)th byte is received.
Figure 21.19 shows the timing of operations when the maximum number of transfer bytes has
been reached but reception is not complete.
[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)
Slave
reception
IERSR
RXEDLE
RXEPE
RXERTME
Dn+1Dn-1 Dn
HD
MA SA CT
DL
D1 D2
When Dn + 1 is received
When Dn + 1 is received
When Dn + 1 is not received
Figure 21.19 Timing of Operations when Reception Has Not Been Completed
Within the Maximum Number of Transfer Bytes