Timing generator, solid-state imaging device and camera system
View Patent ↗A timing generator, includes: a first memory circuit that stores timing generation information; a first register for holding the timing generation information in the first memory circuit; a first external input part for accessing to the first register so as to rewrite data therein; a selector that selects one of the first memory circuit and the first external input part in order to conduct writing of data in the first register; and a pulse generation part that generates a pulse timing in accordance with the timing generation information held in the first register so as to output a single or a plurality of pulses. A pulse timing required for driving a solid-state imaging device and the like can be generated easily and the timing generation can be rewritten externally.
1. A timing generator comprising:
a first memory circuit that stores timing generation information;
a first register for holding the timing generation information in the first memory circuit;
a second register that holds control function information as the timing generator;
a first external input part for accessing the first register so as to rewrite data therein;
a selector that selects one of the first memory circuit and the first external input part in order to conduct writing of data in the first register; and
a second external input part that supplies the selector with a selection signal;
a pulse generation part that generates a pulse timing in accordance with the timing generation information held in the first register and the control function information held in the second register so as to output a single or a plurality of pulses;
an input control part that selects either the first register or the second register in which data input from the first external input part is to be written,
wherein the selector selects data to be input in the first register from an output of the first memory circuit and an input out of the input control part in accordance with the selection signal supplied from the second external input part, and
during a time period when the data input from the first external input part is written into the first register, the pulse generation part is initialized; and
wherein during a time period when data is written in the first register, an output of the pulse generation part is fixed at any one of a high, a low and a high impedance state and after completion of the writing of the data in the first register, a pulse is output in accordance with the timing generation information held in the first register.
2. The timing generator according to claim 1 ,
wherein the first memory circuit stores pulse generation information complying with N different modes (N denotes a natural number), the pulse generation information containing: data (COM) common to the respective modes; and data (D 1 to DN) different for each mode,
the first register holds the data region (COM) and at least one of the data (D 1 to DN),
wherein if the selector selects the first memory circuit, data corresponding to a configured mode among the data D 1 to DN is written in the first register, and if the selector selects the first external input part, data corresponding to a configured mode is written from the first external input part to the first register.
3. The timing generator according to claim 1 ,
wherein the first external input part enables accessing to the first register and the second register independently so as to rewrite internal data therein.
4. The timing generator according to claim 3 , further comprising:
a second memory circuit; and
a data comparator that compares the control function information held by the second register with data in the second memory circuit,
wherein the control function information held in the second register is changeable in accordance with a result of the comparison by the data comparator.
5. The timing generator according to claim 4 , wherein data in the second register is rewritten in an arbitrary logic of at L or a H level in accordance with an output of the data comparator.
6. The timing generator according to claim 1 ,
wherein during a time period when writing is conducted from the first memory circuit or the first external input part to the first register, the timing generator is initialized except for the first memory circuit and the first register.
7. The timing generator according to claim 1 , further comprising a counter circuit that reverses an output from an initial state in response to an edge of a pulse input from the third external input part as a trigger, and holds the same, wherein the reversed state returns to the initial state after counting a predetermined time period,
wherein the input control part outputs the data input from the first external input part to either the selector or the second register in accordance with the output of the counter circuit.
8. A solid-state imaging device provided with the timing generator according to claim 1 .
9. A camera system provided with the timing generator according to claim 1 .