Datasheet

Section 14 IEBus™ Controller (IEB) [H8S/2258 Group]
Rev. 6.00 Mar. 18, 2010 Page 536 of 982
REJ09B0054-0600
Dn H MA SA CF LF D1 D2 Dn-1 Dn
IECTR
RE
CMX
MRQ
SRQ
SRE
RxRDY
RxS
RxF
IERxI (RxRDY)
(TO DTC)
IERxI (RxRDY)
(TO CPU)
IERSI
(TO CPU)
IECMR
IEFLG
IERSR
Interrupt
(1) (2)
(2)
(3)
(4)
(4) (9)
(5) (6)
(7)
(5) (6) (7)
(8)
(9)
(9)
Slave reception Master reception
H: Header, MA: Master address field, SA: Slave address field,
CF: Control field, LF: Message length field, D1, D2,..., Dn-1, Dn: Data field
DTC transfer
of 1st byte
Master reception request
DTC transfer
of (n-2)th byte
DTC transfer
of (n-1)th byte
DTC transfer
of nth byte
Figure 14.11 Master Receive Operation Timing
14.4.4 Slave Transmission
This section shows an example of performing a slave transmission using the DTC after slave
reception.
(1) IEB Initialization
(a) Setting the IEBus Control Register (IECTR)
Enable the IEBus pins, select the signal polarity, and select a clock supplied to the IEB. Clear
the LUEE bit to 0 because transfer by the DTC is performed.
(b) Setting the IEBus Master Unit Address Registers 1 and 2 (IEAR1 and IEAR2)
Specify the master unit address and specify the communications mode in IEAR1. Compare
with the slave address in the communications frame and receive the frame if matched.