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CHAPTER 17
IEBus CONTROLLER (
PD178096A, 178098A, 178F098 ONLY)
User’s Manual U12790EJ2V0UD
Notes 1. The
PD178098A Subseries supports the IEBus controller when fX = 6.3 MHz. When fX = 4.5 MHz,
the IEBus controller is not supported.
2. Automatic master reprocessing: After generating the master request, if the master request is cancelled
by arbitration, etc., the bus is released and the master automatically
re-issues the master request.
Communication start preprocessing (data setting)
Setting and management of each communication
status
Writing data to transmit buffer
Reading data from receive buffer
Bit processing (modulation/demodulation, error
detection)
Field processing (generation/management)
Arbitration result detection
Parity processing (generation/error detection)
Automatic return of ACK/NACK
Automatic data reprocessing
Automatic master reprocessingNote 2
Transmission processing such as automatic slave
status transmission
Multiple-frame reception processing
17.2 Simple IEBus Controller
The
PD178098A Subseries has a newly developed IEBus controller. The functions of this IEBus controller are
limited compared with the conventional IEBus interface functions of the existing models (provided in the 78K/0 Series).
Table 17-7 compares the conventional IEBus interface functions of the existing models with the simple IEBus
interface functions of the
PD178098A Subseries.
Table 17-7. Comparison of Existing and Simple IEBus Interface Functions
Item
Conventional Functions (IEBus of 78K/0)
Simple Version (IEBus Incorporated in
PD178098A Subseries)
Communication mode Modes 0, 1, and 2
Fixed to mode 1
Internal system clock
fX = 6.0 (6.29) MHz
fX = 6.3 MHzNote 1
Internal buffer size
Transmit buffer: 33 bytes (FIFO)
Transmit/receive data register
Receive buffer: 40 bytes (FIFO)
Up to 4 frames can be received.
CPU processing
Hardware processing
Communication start preprocessing (data setting)
Setting and management of each communication
status
1-byte data write processing
1-byte data read processing
Management of transmission such as slave status
Management of multiple frames, master request
reprocessing
Bit processing (modulation/demodulation, error
detection)
Field processing (generation/management)
Arbitration result detection
Parity processing (generation/error detection)
Automatic return of ACK/NACK
Automatic data transmission reprocessing