Datasheet

Section 14 IEBus™ Controller (IEB) [H8S/2258 Group]
Rev. 6.00 Mar. 18, 2010 Page 521 of 982
REJ09B0054-0600
Bit Bit Name
Initial
Value
R/W Description
0 ACK 0 R/W Acknowledge bit Status
Indicates the data received in the acknowledge bit of the
data field.
• Acknowledge bit other than in the data field
The IEB terminates the transmission and enters the
wait state if a NAK is received. In this case, this bit and
the TxE flag are set to 1.
• Acknowledge bit in the data field
The IEB retransmits data up to the maximum number of
bytes defined by communications mode until an ACK is
received from the receive unit if a NAK is received from
the receive unit during data field transmission. In this
case, when an ACK is received from the receive unit
during retransmission, this flag is not set and
transmission will be continued. When transmission is
terminated without receiving an ACK, this flag is set to
1.
Note: This flag is invalid in broadcast communications.
[Setting condition]
When the acknowledge bit of 1 (NAK) is detected
[Clearing condition]
When writing 0 after reading ACK = 1