Sharp ER-A450T Service Manual page 28

3) SSP register access method
Access to SSP break address register is performed through the tem-
porary register as shown below:
A19 A18 A17 A16 A15
Temporary
1
Enable flags can be accessed individually.
Though enable register can be accessed individually, writing to
break address registers and
writing to break address register
Therefore, set and to temporary, then write into
Since the temporary register is commonly used by BAR sets, the
following register setting is performed after completion of setting of
each break address register.
SSP control method
Access to the enable register and the break address register is only
possible when writing to them from the CPU.
bit 7 6 5 4 3
0 0 0 CMP4 CMP3 CMP2 CMP1 CMP0 (FFFFFFH)
7. PRINTER control circuit
1) Block diagram
TPRC1
Address bus
Data bus
CPU
MPCA7
Fig. 7-1
The thermal printer (PR-45M) is controlled by the thermal printer
controller (TPRC1). The PB-RAM connected to TPRC1 serves as
a print data buffer.
Temporary
2
WR
is performed at the same time as
through the temporary register.
last.
2 1 0
P.B-
PRINTER
RAM
(PR-45)
A8 A7 A2
WR
3
Fig. 6-5
Information on which break register the SSP break is detected and is
read as binary data by reading address FFFFFFH (*1).
If there are 32 break registers, the binary expression is made with the
above 5 bits, and 0th is "00000
When detected simultaneously by two or more break registers, one
with the smaller BAR number is read as binary data.
The break signals (NMI) and the above detection data (CMP0~4) are
held until the above detection data are read. Thus, the reading is
made in the NMI sub routine. (Clear by FFFFFFH read.)
1: FFFFFFH is not fully decoded. (FFFF00H~FFFFFFH). There-
fore any unnecessary read access in parentheses should not
be performed.
2) Paper feed circuit
RAS/JAS
RBS/JBS
TPRC1
RCS/JCS
RDS/JDS
A pulse motor is used as the paper feed motor.
Drive sequence of the pulse motor is as follows:
4 – 20
EN
4
" and 31st is "11111 ."
B B
RPFA/JPFA
RPFB/JPFB
B A
4AC16
RPFC/JPFC C
M
RPPD/JPFD
D
VRCOM/VJCOM