UPD6708 datasheet(46/72 Pages) NEC

46 / 72 page

µPD6708

Table 7-3. Placing Receive Data in RDB

Parameter/

Areas where RDB is read

Time (

µs) Note

Communication Data

Mode 0

Mode 1

Mode 2

Slave address

When ACK bit is transmitted in message length field

Control bits

Message length bits

Receive data (first byte)

When first ACK bit is transmitted in data field

Approx. 1580

Approx. 400

Approx. 290

Receive data (second byte)

When second ACK bit is transmitted in data field

Approx. 3160

Approx. 800

Approx. 580

Receive data (N-th byte)

When N-th ACK bit is transmitted in data field

Approx. 1580

× N Approx. 400 × N Approx. 290 × N

Note

Minimum time after the “master reception start” return code is placed in STR and an interrupt request is generated.

7.4

Slave Reception

If a slave unit receives AH, BH, EH, or FH as control bits from the master unit and receive data or a command, the following

will occur.

(1)

When the slave unit returns an acknowledge in the message length field, the master address, control bits and message

length bits are placed in RDB as shown in Figure 7-5, a “ slave reception start” return code (8H) is placed in STR, and

an interrupt request is generated.

Figure 7-5. Data Exchange During Slave Reception (Contents of RDB)

(2)

Each time one byte of receive data is received, it is placed in RDB.

(3)

Each time 20 bytes (RDB capacity) of receive data are received, if RDB is full, a “slave receive buffer full” return code

(9H) is placed in STR, and an interrupt request is generated.

(4)

After the final data of one frame is placed in RDB, a “slave reception normal termination” return code (AH) is placed

in STR and an interrupt request is generated.

(5)

If a communication error occurs during reception and communication stops without receiving all of the data transmitted

from the master unit, a “termination during slave reception” return code (BH) is placed in STR and an interrupt request

is generated.

The areas where the

µPD6708 places receive data, etc., in RDB are shown below.

Master Address (12 Bits)

First Byte

Second Byte

Third Byte

Fourth Byte Onward

RDB

Message Length Bits

Control Bits

UPD6708 数据表(PDF) 46 Page - NEC

UPD6708 数据表(HTML) 46 Page - NEC

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

数据表下载