![](http://datasheet.mmic.net.cn/370000/UPD6708_datasheet_16740712/UPD6708_30.png)
30
μ
PD6708
5.
COMMUNICATION CONTROL COMMANDS
The operation conditions of the
μ
PD6708 can be controlled by giving it a command from the host controller.
After a communication using the appropriate procedure (see
8.3.2 “Communication control command processing
routine”
), it is executed in a period in which communication is not being performed (standby state).
5.1
Overview of Communication Control Commands
Table 5-1. Overview of Communication Control Commands
Command Name
Description
INIT
(Initialize)
Sets local address and initializes.
SETSA
(Set slave address)
Sets the unit to communicate with.
MREQ1
(Master request 1)
Communicates as a master unit.
MREQ2
(Master request 2)
Continues in previous condition as the master unit and communicates.
ABORT
(Abort)
Aborts communications.
SETSD
(Set slave data)
Sets data for slave transmission.
GETSTA (Get status)
Reads communication status.
SETREV (Set receive)
Sets reception disabled state/enabled state.
(1)
Write command
The command codes and command parameters for the write commands are shown in Table 5-2.
Table 5-2. Command Codes and Command Parameters of Write Commands
Note
Only set when transmitting.
Caution Note that even if the host controller makes a mistake in setting the number of command parameter bytes,
an error message will not be returned by the
μ
PD6708, and command processing will be performed as
though it were a correctly set command.
Command Code
(Lower 4 Bits of
CMR)
Command Parameters (WDB)
Command Name
First Byte
Second Byte
Third Byte
Fourth Byte
INIT
0000
SETSA
0001
MREQ1
0010
MREQ2
0011
ABORT
0100
SETSD
0101
SETREV
0111
Control bits
Broad-
cast bits
Unit address
Condition
setting
code
Slave address
0000
Number of master
transmit data bytes
Note
Master transmit
data (first byte)
Note
Master transmit
data (second byte)
Note
Number of slave
transmit data bytes
Slave transmit
data (first byte)
Slave transmit
data (second byte)
Slave transmit
data (third byte)
Reception status
code
MSB
LSB
MSB
LSB
MSB
LSB
MSB
LSB
MSB
LSB