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The Subcode Q Output Circuit
Code
$09
$89
It is possible to read the subcode Q from the SQOUT pin by inputting a clock into the CQCK pin. Of the 8-bit subcodes,
the "Q" signal is useful in accessing musical selections, in displays, etc. WRQ is only high when the CRC has been
passed and the address in the subcode Q format is "1." (See Note 1.) When the microcontroller detects this high level, it
can transmit a CQCK signal to read the data from SQOUT in the order shown below. When the CQCK transmission
begins, data changes in the internal registers of the DSP are inhibited. Once the microcontroller has completed its read,
RWC temporarily goes high, enabling data updating. At this time, WRQ goes low. Because WRQ goes low after being
high for 11.2 ms, the CQCK input starts during the interval when WRQ is high. The data can be read beginning with the
least significant bit.
Note 1: This conditions is ignored if an address-free command is sent (corresponding to the CDV).
CONT
INDEX (POINT)
AMIN (PMIN)
ASEC (PSEC)
AFRAME (PFRAME)
* The WRQ pin normally indicates the subcode Q standby; however, when in the track counter mode and when there is
an internal bake, it becomes a different monitor. (See the track count and internal brake items.)
* This IC becomes active when the CS pin is low, and the subcode Q data is output from the SQOUT pin. When the CS
pin is high, the SQOUT pin enters a high impedance state.
Pin 66: WRQ, Pin 62: RWC, Pin 65: SQOUT, Pin 64: CQCK, Pin 15 CS
COMMAND
ADDRESS FREE
ADDRESS 1
ADR
TNO
MIN
SEC
FRAME
ZERO
Sub Q data
LC78626KE
RES = low
The items within the parentheses are for the read-in area.
No. 5995-20/34
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