Panasonic KX-FT21BX Service Manual page 87

ROM (IC2)
A0-17
D0-7
+24V
IC7
+5V
TO
CIS
CLK, SIG
24V
Q13
TO
STBI-2,THLAT
THERMAL HEAD
THCLK,THDAT
5V
(IC4)
RESET
BACK UP
Digital Block Diagram
RD
20.736MHz
LED ON
ASIC
CIS-CTL
VOL
IC1
TH ON
HEAD-CTL
XWDERR
32.768KHz 24MHz
T0,T2~T5
SRAM (IC3) ANALOG FRONT END (IC5)
A0-17
D0-7
RD
WR
KSTART,KLATCH,KSCLK,KTXD,KRXD,KIN0,KIN1,KIN2,KIN3
RS,E
TO SRAM (IC3)
ANALOG PORT CONTROL
I/O
ANALOG SW
(IC6)
TXOUT
RXIN
H/S RX
H/S TX
TO
OPE PANEL
TO
(IC7) MOTOR
MOTOR
DRIVER
TO ANALOG
TX
RX
SP