Epson 4003353 - Manual (Page 51)

Stylus Service Manual Operating
2.3.2.6 Controller
Data from the host computer is received automatically by the signal via the external
Centronics interface. The data is input into the input buffer on the D-RAM At this time,
detects the rising edge of the external signal and outputs the (strobe
request) signal to the CPU. When the CPU detects this signal, the controller in the CPU
sends a bus request to the bus controller in the CPU, and then the CPU releases the bus line. Due to
this, the external data is transported into the memory, bypassing the CPU.
CPU H8 (ICI)
ACK
BUSY
STBDMA
132 9
➤
, --------------- .--------------,
4
DMAC BAC
‘. . . . . .
Figure 2-26. Controller Operation
Memory
Rev. A 2-21