Samsung Electronics
5-1
5. Circuit Descriptions
5-1 Main PBA
The main board consists of CPU, System controller, Fax modem, Modem interface, Image processor,
Printing ASIC, I/O port gate array. Detail description is provided below.
5-1-1 Memory & I/O Map
BMC (Bus and Memory Controller) in the system
controller interfaces directly with CPU, ROM,
SRAM, and I/O.
Figure 5-1 Memory & I/O Map
FFFFF
F00000
EFFFF
E00000
DFFFF
C00000
BFFFF
800000
7FFFF
400000
3FFFF
000000
ON-CHIP INTERNAL REGISTER
(1 Mbyte)
I/O (1 Mbyte)
SRAM(2 Mbyte)
EPROM (4 Mbyte)
DRAM (4 Mbyte)
DRAM (4 Mbyte)
CPU
A16-A23
ADO-AD15
INT, HOLD
CAS, WEO, WE1
WEO, WE1
DRQ, DAK, TRIG
CS, RESET
PIC_ CS
PIC_ INT
PIC_ DRQ
DDIN
PIC DARK
HBE,ADS, DDIN
MCS, RD, WEO
MIRQ
CLOCK
ADO-AD7
MA1-MA5
MODEM
ECP
ADO-AD15
MA1-MA7
SYSTEM
CONTROLLER
ADO-AD15
MA1-MA11
ADO-AD15
MA1-MA5
ADO-AD7
MA1-MA5, A22
CS , CHSYNC
SCLK, SDATA
PRINT
ASIC
T
X
D
R
X
D
L I U
IMAGE
PROCESSOR
(SDIP III)
MEMORY
(DRAM)
5-1-2 CPU and System Controller
Figure 5-2 Hardware Interface Signals