H8SSLASH2224 datasheet(572/1071 Pages) RENESAS

572 / 1071 page

Section 14 IEBus™ Controller (IEB) [H8S/2258 Group]

Rev. 5.00 Aug 08, 2006 page 486 of 982

REJ09B0054-0500

PP A

P A

Field name

Header

Master

address field

Slave address

field

Approximately 7330

µs

Approximately 2090

µs

Approximately 1590

µs

Approximately 1590

× N µs

Approximately 410

× N µs

Approximately 300

× N µs

Control field

Data field

(When

φ = 12 MHz)

Message

length field

Number

of bits

Transfer

time

Mode 0

Mode 1

Mode 2

Note: The value of acknowledge bit is ignored in broadcast communications.

P: Parity bit (1 bit)

A: Acknowledge bit (1 bit)

When A = 0: ACK

When A = 1: NAK

N: Number of bytes

Start

bit

Master

address

Slave

address

Control

bits

Data

bits

Data

bits

Message

length

bits

Broad-

cast

bit

Figure 14.2 Transfer Signal Format

(1) Header

Header is comprised of a start bit and a broadcast bit.

(a) Start Bit

The start bit is a signal for informing a start of data transfer to other units. A unit, which

attempts to start data transfer, outputs a low-level signal (start bit) for a specified period and

then outputs the broadcast bit.

If another unit is already outputting a start bit when a unit attempts to output a start bit, the unit

waits for completion of output of the start bit from the other unit without outputting the start

bit, and then outputs the broadcast bit synchronized with the completion timing.

Other units enter the receive state after detecting the start bit.

(b) Broadcast Bit

The broadcast bit is a bit to identify the type of communications: broadcast or normal.

When this bit is cleared to 0, it indicates the broadcast communications. When it is set to 1, it

indicates the normal communications. Broadcast communications includes group broadcast

and general broadcast, which are identified by a value of the slave address. (For details of the

slave address, see section 14.1.2 (3), Slave Address Field.)

Since there are multiple slave units, which are communications destination units, in the case of

broadcast communications, the acknowledge bit is not returned from each field described in (2)

and below.

H8S/2224 Scheda tecnica(PDF) 572 Page - Renesas Technology Corp

H8S/2224 Scheda tecnica(HTML) 572 Page - Renesas Technology Corp

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 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Scheda tecnica Scarica

Link URL