| 摘要 |
PURPOSE:To prevent the generation of an overflow error by setting up only the original data in a data block to the number of bits larger than that of other data as the transmission main data of PCM code data and transmitting its upper bit as an extra bit. CONSTITUTION:When data accumulated in an accumulator are (a) shown in the figure as the accumulated result of the lower residual data, its scale value is 6. If DPCM code data l is applied as the original data, both data are added to obtain data (c). Since the scale value is still 6, data (d) are transmitted as the main data. Consequently, data (e) is left in the accumulator. When it is assumed that the data block comes to end under such condition and data (f) are applied at the initial time of the succeeding data block and simultaneously the scale value is changed to ''1'', the added result is shown by (g) in the figure and data consisting of 9 bits in stead of 8 bits are sent. Since the scale value is ''1'', data (i) is left in the accumulator. |
