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How to set TE and RE separately to 1 in transmit/receive operation?

Latest Updated:03/18/2009

Question:

In hardware manuals, there is a note that mentions that when in a transmit/receive operation, to set the TE and the RE at one time. Can we set them as “1” separately?

Answer:

The serial interface of the H8 family and the H8S family is divided into a transmit part and a receive part structurally to be used for both asynchronous and functions.

The transmit part and the receive part can be operated individually. When in synchronous transmit/receive data, each part is synchronized and operated.

At the same time, the TE bit and the RE bit play a role in clock source supply gate for each transmitter part and receive part.

When the TE and the RE were set separately, the clock source for the transmit part and the receive part will not work together. As a result, the TE and the RE would not be operated at once.

Therefore please set the TE and the RE to “1” all at once when in transmit/receive operation. 

Also, the same rule applies in the operation mode change from transmit mode (TE=1, RE=0) and receive mode (TE=0, RE=1) to transmit/receive mode (TE=1, RE=1).

In such a mode change case, after setting the serial interface to TE=0 and RE=0, set TE and RE to “1” all at once.

(Note: when the serial interface is set to TE=0 and RE=0, the TxD and RxD pins will be switched to each general port.)

Regardless of a half duplex or full duplex, we recommend you to use transmit/receive mode (TE=1, RE=1) preliminary when in both of transmit and receive operations.

Suitable Products
H8 Family
H8/300H
H8S Family
H8S/2600
H8S/2678, 2678R
H8S/2668
H8S/2655
H8S/2649
H8S/2648, 2646
H8S/2643
H8S/2630, 2639, 2638, 2636, 2635
H8S/2633
H8S/2628
H8S/2626, 2623
H8S/2615
H8S/2612
H8S/2500
H8S/2556, 2552, 2506
H8S/2400
H8S/2437
H8S/2300
H8S/2378, 2378R
H8S/2368
H8S/2398, 2357
H8S/2355
H8S/2350
H8S/2345
H8S/2339
H8S/2329
H8S/2319
H8S/2200
H8S/2282, 2280
H8S/2276
H8S/2268, 2264
H8S/2258, 2239, 2238, 2237, 2227
H8S/2245
H8S/2215
H8S/2214
H8S/2218, 2212
H8S/2100
H8S/2199R
H8S/2194
H8S/2189R
H8S/2172
H8S/2168
H8S/2169, 2149
H8S/2158
H8S/2148, 2144
H8S/2144B,2134B
H8S/2140B
H8S/2138, 2134
H8S/2128, 2124
H8S/2114R
H8S/2111B
H8S/2110B