II-5
(8)
CDCC parallel I/O
<Data receiving>
There are two modes in this unit. One is the CPU receiving mode and the other is
the DMA receiving mode. In the CPU receiving mode the CPU receives the
command data from the PC, and after the CPU is switched to the DMA mode, it
receives the image data and writes to the DRAM directly.
CPU Receiving Mode
90 µsec
STROBE
BUSY
ACK
STROBE
BUSY
ACK
0.5 µsec
0.5 µsec
1.5 µsec
BUSY goes HIGH at the falling edge of STROBE. The data (8 bits) from the PC is
latched in the data buffer at the rising edge of STROBE. The pulse width of ACK differs
according to the speed MODE as shown above. BUSY goes LOW at the rising edge of
ACK.
<IEEE1284 support>
This supports the IEEE1284 data transfer with the following mode.
Nibble mode
Byte mode
ECP
mode
(9)
Data extension
This circuit extents the compressed image data which are received from the PC,
and writes the bit map data to the FIFO.
(10)
Software support
Supports 16 x 16 rotation, bit expansion, bit search, and decimal point change.
(11)
EEPROM I/O
One output port and one I/O port are assigned.
DMA Receiving Mode
Содержание HL-720
Страница 1: ...SERVICE MANUAL MODEL HL 720 730 730Plus R LASER PRINTER ...
Страница 36: ...II 19 1 3 10 Engine I O HL 720 Fig 2 21 shows the engine interface circuit Fig 2 21 ...
Страница 37: ...II 20 HL 730 730Plus Fig 2 22 shows the engine interface circuit Fig 2 22 ...
Страница 61: ... Fig 3 18 2 4 1 1 1 ...
Страница 92: ...SERVICE MANUAL MODEL HL 760 R LASER PRINTER ...
Страница 109: ...II 8 1 3 4 DRAM Two 4M bit DRAMs x 16bits are used as the RAM Fig 2 6 ...
Страница 113: ...II 12 1 3 10 Engine I O Fig 2 12 shows the engine interface circuit Fig 2 12 ...
Страница 114: ...II 13 1 3 11 Paper Feed Motor Drive Circuit Fig 2 13 ...
Страница 133: ...Appendix 2 Main PCB Circuit Diagram 1 3 CODE UK3227000 B48K272CIR 1 3 NAME ...
Страница 134: ...Appendix 3 Main PCB Circuit Diagram 2 3 CODE UK3227000 B48K272CIR 2 3 NAME ...
Страница 135: ...CODE UK3227000 B48K272CIR 3 3 NAME Appendix 4 Main PCB Circuit Diagram 3 3 ...