UPD72042BGT NEC [NEC], UPD72042BGT Datasheet - Page 57

• Manufacturer Part Number: UPD72042BGT
• Description: LSI DEVICE FOR Inter Equipment Bus (IEBus) PROTOCOL CONTROL
• Manufacturer: NEC [NEC]

for master reception, slave reception, or broadcast reception.
in RBF until RBF becomes full.
to the microcomputer.
RBF is a 40-byte FIFO buffer used to hold a transmitter address, control bits, data-length bits, and reception data
RBF can be read by the microcomputer when the REP flag of the STR register is 0 (indicating that RBF is not empty).
When an optional function is set in the CMR register with MFC = 1, multiple communication frames can be held
In master reception, slave reception, and broadcast reception, the format below is used to transfer data from RBF
RBF
Reception buffer
Byte 40
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Transmitter address (low-order 4 bits)
Transmitter address (low-order 4 bits)
High-order 4 bits
Transmitter address (high-order 8 bits)
Transmitter address (high-order 8 bits)
Second byte of reception data
Second byte of reception data
First byte of reception data
First byte of reception data
Last reception data
Last reception data
Data-length bits
Data-length bits
Data Sheet S13990EJ3V0DS
RBF
Low-order 4 bits
Control bits
Control bits
Address
Read/write
When reset : Undefined
Communication frame 1
Communication frame 2
: 1110B (EH)
: Read
PD72042B
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