gm82c765b ETC-unknow, gm82c765b Datasheet - Page 11

• Manufacturer Part Number: gm82c765b
• Description: Floppy Disk Subsystem Controller
• Manufacturer: ETC-unknow

The GM82C765B Floppy Disk Subsystem
Controller is a CMOS LSI device that provides
all the needed functionality between the host
u-processor peripheral Bus and the cable
Connec-tor to the Floppy Disk Drive. This CHIP
in-tegrates; Formatter/Controller Data Separation,
Write Precompensation, Data rate Seletion,
Clock generation, Drive interface drivers and
receivers.
Fig 1. GM82C765B Internal Block Diagram
3. ARCHITECTURE
DACK
LDCR
CLK1
LDOR
CLK2
DRV
DMA
8 Bit
DATA
BUS
IRQ
RD
WR
CS
A0
TC
INTERFACE
CRYSTAL
OSc 2
HOST
REGISTER
CONTROL
GENERATOR
DIGITAL DATA
SEPARATOR
CLOCK
TIMING
AND
SCLK
TIMER
MS
MCLK
01
02
WCLK
STATUS REG
MASTER
DATA ENCODER
MACHINE
DECODER
SATE
ALU
11
HOST INTERFACE
The host interface is the host microprocessor
peripheral bus. This bus is composed of eight
control signals and eight data signals. In the
special or PC AT modes, IRQ and DMA request
are tri-stated and qualified enable, internally
provided by the operations register. The data bus,
DMA, and IRQ outputs are designed to handle 20
LS-TTL loading.
INSTRUCTION
PROGRAM
COUNTER
DECODE
LOGIC
24
FLAG
RAM
CRC GENERATOR
REGISTER
8 Bit INTERNAL DATA BUS
8
DATA
1KÏ16
ROM
PRECOMPENSATION
PLCC version of GM82C765B only
OPERATION
REGISTER
WRITE
INTERFACE
REGISTER
CONTROL
DISK
GM82C765B
WD
PCVAL
RDD
WE
HS
HDL
STEP
DIRC
RWC
DS
TROO
IDX
WP
DCHG
1
4
*