UPD72042BGT NEC [NEC], UPD72042BGT Datasheet - Page 38

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

transmission and slave data transmission.
is not full).
microcomputer.
[Byte 1]: Number of bytes of transmission data
[Bytes 2 and up]: Transmission data
38
TBF is a 33-byte FIFO buffer used to hold the number of bytes of transmission data and transmission data for master
TBF can be written from the microcomputer when the TFL flag of the STR register is set to 0 (indicating that TBF
In master transmission and slave data transmission, the following format is used to load data into TBF from the
Between 1 and 256 bytes can be set.
As much transmission data as is set in byte 1 is set in byte 2 and subsequent bytes.
TBF
Transmission buffer
Number of bytes of
transmission data
255
256
1
2
Byte 1
Byte 2
Byte 3
Byte 33
Data set in byte 1 of TBF
Number of bytes of transmission data
Second byte of transmission data
First byte of transmission data
FFH
01H
02H
00H
Data Sheet S13990EJ3V0DS
TBF
Address
Read/write
When reset : Empty
: 1110B (EH)
: Write
PD72042B