PD72042B_15 Datasheet, PDF (20/92 Pages) Renesas Technology Corp – LSI DEVICE FOR Inter Equipment BusTM (IEBusTM) PROTOCOL CONTROL

µPD72042B
Table 2-3 Meanings of the Control Bits
Bit 3^{Note 1} Bit 2
0H
0
0
1H
0
0
2H
0
0
3H
0
0
4H
0
1
5H
0
1
6H
0
1
7H
0
1
8H
1
0
9H
1
0
AH
1
0
BH
1
0
CH
1
1
DH
1
1
EH
1
1
FH
1
1
Bit 1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Bit 0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Function^{Note 2}
Read slave status (SSR)
Undefined
Undefined
Read data and locking
Read lock address (low-order 8 bits)
Read lock address (high-order 4 bits)
Read slave status (SSR) and unlocking
Read data
Undefined
Undefined
Write command and locking
Write data and locking
Undefined
Undefined
Write command
Write data
Notes 1. The transfer direction of the data-length bits of the subsequent data-length field and data in the data
field changes according to the value of bit 3 (MSB).
When bit 3 is 1: Transfer from the master unit to the slave unit
When bit 3 is 0: Transfer from the slave unit to the master unit
2. The values of control bits 3H, 6H, AH, and BH specify locking and unlocking. When an undefined value,
1H, 2H, 8H, 9H, CH, or DH, is transmitted, no acknowledge signal is returned.
Once a unit has been locked by a master unit, the locked unit rejects the control bits received from other than the
master unit that requested the lock, unless the value of the control bits is one of the values listed in Table 2-4. Then,
the unit does not output the acknowledge bit.
Table 2-4 Control Field Acceptable to a Locked Slave Unit
Bit 3
Bit 2
Bit 1
Bit 0
Function
0H
0
0
0
0
Read slave status
4H
0
1
0
0
Read lock address (low-order 8 bits)
5H
0
1
0
1
Read lock address (high-order 4 bits)
(1) Reading the slave status (SSR) (control bits: 0H, 6H)
A master unit can read the slave status (0H, 6H) to determine why the slave unit did not return the acknowledge
bit (ACK).
The slave status is determined from the result of the communication last performed by the slave unit.
All slave units can provide slave status information.
Table 2-5 lists the slave status meanings.
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Data Sheet S13990EJ3V0DS