H8SSLASH2224 datasheet(631/1071 Pages) RENESAS

631 / 1071 page

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

Rev. 5.00 Aug 08, 2006 page 545 of 982

REJ09B0054-0500

14.6.7

Notes on DTC Specification

When transmit or receive data is transferred by the DTC, bit 5 (for transmission) or bit 6 (for

reception) in DTCERG must be set by the bit manipulation instruction (such as BSET or BCLR).

In this case, other bits (bits 7 and 4 to 0) in DTCERG must not be set to 1.

14.6.8

Error Handling in Transmission

Figure 14.15 shows the operation when a timing error occurs.

When a timing error occurs in data transmission (1), there is a possibility that the next data is

already transferred to the transmit buffer by the DTC and the TxRDY flag that is the DTC

initiation source is already cleared to 0 (2).

In this case, if retransfer is performed, data remained in the transmit buffer (previous frame data)

is transmitted as the first byte data of the data field (3).

To avoid this error, in master transmission, the first byte data in the data field should be written to

the transmit buffer by software instead of using the DTC. After that, data can be transferred by the

DTC. In this case, the SAR (transfer source address) and CRA (transfer counter) should be

specified as follows.

• An address of the on-chip memory that stores the second byte data → SAR

• The number of bytes specified by message length –1 → CRA

(1)

(2)

(3)

IETSR

Transmit error frame

Timing error

Legend:

MA:

SA:

CF:

LF:

D1, D2, ...Dn-1, Dn: Data field

Start bit, broadcast bit

Master address field

Slave address field

Control field

Message length field

1st byte data

transferred

by DTC

1st byte data

transferred

by DTC

2nd byte data

transferred

by DTC

Retransfer frame

TxRDY

IETEF

TTME

Figure 14.15 Error Processing in Transfer

H8S/2224 Scheda tecnica(PDF) 631 Page - Renesas Technology Corp

H8S/2224 Scheda tecnica(HTML) 631 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