Sony UP-D2600, Service Manual

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4-19
UP-D2600/V1(E)
[Input and Output Timing]
nPRINTING and nHEAD_ACTIVE_IN signals are enable signals of the thermal head. When both these
signals are L, the thermal head enters the print enable mode. The NHEAD_ACTIVE_IN (P) signal is also
use as the enable signal of IC207, IC208 and IC210. When this signal is “L”, the IC is in the print enable
mode. In this mode, when the rising edge of PRINT_PULSE_IN signal is input to the PQC IC (IC207),
an nDREQ signal that indicates print data receive enable state is output to the IF-787 or IF-788 board,
DMA transmission of first-line data is received. If the rising edge of a next PRINT_PULSE_IN signal is
input to PQC IC, nHEAD_ACTIVE_P and nPRINT_PULSE_P signals are output to the next-stage head
drive IC (IC208), the first-line data is processed the image, and the nPRINT_DREQ signal from next-
stage head drive IC is waited for DMA transmission.
The head driving IC (IC208) receives the PRINT_PULSE_P signal from PQC IC (IC207) and outputs an
nPRINT_DREQ signal. After that, 1-line 8-bit print data is DMA-transferred in synchronization with the
PRINT_DCK signal from PQC IC.
Taken the next PRINT_PULSE_P signal is input, data is transmitted to the thermal head as 8-port serial
data together with a shift clock (HEAD_CK), data latch output (HEAD_LATCH), and strobe output
(HEAD_STRB). DMA transmission of second line data is also received in parallel.
As described above, the input first line data is synchronized with the second PRINT_PULSE_IN signal
and transmitted to head driving IC. It is output to the thermal head in synchronization with the third
PRINT_PULSE_IN signal. The PRINT_PULSE_IN signal is input to PQC IC with exceeding the
number of actual print lines by two.
HA-IN (TP204)
PP-IN (TP206)
FDREQ (TP220)
HDLATCH
(TP222)
HDSTRB
(TP223)
IF
PQC IC
PQC IC
HDC IC
HDC IC
VDC IC
HEAD
FD0-D7
(TP211-218)
PD0D7
HD1-16
HDCX (TP221)
FDCX (TP219)
PHA (TP247)
PPP (TP250)
PDREQ (TP240)
PDACT (TP245)
PDCX (TP243)