H8S2258 Datasheet, PDF (601/1071 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8S Family/H8S/2200 Series

Section 14 IEBus™ Controller (IEB) [H8S/2258 Group]
14.3.18 IEBus Transmit/Runaway Status Register (IETSR)
IETSR detects transmit data ready, transmit start, transmit normal completion, transmit completion
with an error, or runaway states. Each status flags in IETSR corresponds to a bit in the IEBus
transmit/runaway interrupt enable register (IEIET) that enables or disables each interrupt.
Initial
Bit Bit Name Value R/W Description
7
TxRDY
1
R/W Transmit Data Ready
Indicates that the next data can be written to IETBR since
IETBR is empty. This flag is automatically cleared by DTC^*
data transfer. When data is transmitted by the CPU, this
flag must be cleared by software. This flag is cleared by
writing 0 after reading a 1 from this flag.
[Setting conditions]
• Immediately after reset
• When data can be written to IETBR (: When IEB has
loaded data from IETBR to the transmit shift register)
[Clearing conditions]
• When writing 0 after reading TxRDY = 1
• When data is written to TBR by the DTC by a TxRDY
request.
Note: This flag is not cleared on the end byte of DTC
transfer.
6 to 4 
All 0

Reserved
These bits are always read as 0 and cannot be modified.
3 IRA
0
R/W IEBus Runaway State
Indicates that the on-chip microprogram for IEBus control is
in the runaway states. This flag is set to 1 when a runaway
occurs during either IEBus transmission or reception. (This
flag is not a transfer specific flag and is also set for a
reception runaway.)
[Setting condition]
When the on-chip microprogram is in the runaway states
[Clearing condition]
When writing 0 after reading IRA = 1
Rev. 5.00 Aug 08, 2006 page 515 of 982
REJ09B0054-0500