UPD72042BGT NEC [NEC], UPD72042BGT Datasheet - Page 46

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

46
0000
0001
0010
0011
MARC
(b) Master reception
Master reception is performed when the microcomputer performs the setting below.
• Master reception setting
Table 4-3 indicates the MARC return codes for master reception.
1 In the low-order 4 bits of the MCR register, control bits (0000, 0011, 0100, 0101, 0110, or 0111) are set
2 In COMC of the CMR register, a command (1000 or 1001) for requesting master communication is set.
for slave-to-master data transfer.
1. Meaning: Master transmission is started.
2. Occurrence condition: This return code is issued when the master address field in a communication
1. Meaning: Master transmission data is not available.
2. Occurrence condition: This return code is issued if the next transmission data is not set in TBF during
3. Microcomputer processing: If data consisting of one or more bytes is not set in TBF within the time
1. Meaning: Master transmission was terminated normally.
2. Occurrence condition: This return code is issued when as much data as the amount specified in the
1. Meaning: Master transmission was aborted.
2. Occurrence condition: This return code is issued in any of the following cases. In each case, the MARQ
frame has been transmitted, and the unit has won the arbitration to become the master unit.
master transmission.
below, transmission may be terminated prior to its completion.
• Transmission data setting time:
data-length field has been transmitted normally. In this case, the MARQ flag of the FLG register changes
from 1 to 0.
flag of the FLG register changes from 1 to 0.
• When the unit has lost the arbitration to become the master unit.
• When a transmission is stopped because the NAK is returned from the slave unit at the end of the slave
• When a communication is terminated prior to the transmission of as much data as the amount specified
address field, the control field, or the data-length field of a communication frame (excluding the broadcast).
in the data-length field of a communication frame.
Table 4-2 MARC Return Codes for Master Transmission
Data Sheet S13990EJ3V0DS
Approx. 1570 s (mode 0)
Approx. 390 s (mode 1)
Description
PD72042B