Datasheet

Section 14 IEBus™ Controller (IEB) [H8S/2258 Group]

Rev. 6.00 Mar. 18, 2010 Page 500 of 982

REJ09B0054-0600

Bit Bit Name

Initial

Value

R/W Description

2 LUEE 0 R/W Last Byte Underrun Enable

Sets whether to generate an underrun error when the last

data field byte is transferred in data transmission.

If the IEB reads from IETBR when the TxRDY flag is set

(the transmit buffer register (IETBR) is empty), an underrun

error occurs. In transmission using the DTC, an underrun

error occurs at the last byte transmission if the CPU did not

clear the TxRDY flag, because the DTC does not clear the

TxRDY flag. When the DTC is used, set this bit to 0 to

mask an underrun error generated at the last byte

transmission. When the DTC is not used, set this bit to 1 to

generate an underrun error at the last byte transmission.

0: An underrun error does not occur at the last byte

transmission (when using the DTC)

1: An underrun error does not occur at the last byte

transmission (when not using the DTC)

1, 0 ⎯ All 0 ⎯ Reserved

This bit is always read as 0 and cannot be modified.

14.3.2 IEBus Command Register (IECMR)

IECMR issues commands to control IEB communications. Since this register is a write-only

Methods for Registers with Write-Only Bits.