LC8953 Просмотр технического описания (PDF) - SANYO -> Panasonic
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LC8953 Datasheet PDF : 9 Pages
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LC8953
Internal Functional Blocks
The PUPPET consists of about 10 functional blocks. See
the “Block Diagram”.
PADEC (Programmable Address Decoder)
The PADEC functional block is used to generate the chip
select (CS) signals for ROM, RAM, I/O devices and so on.
The CS signal addresses are programmable, which enables
address allocation specific to your system configuration.
DTAKGEN (Programmable DTACK Generator)
The DTAKGEN functional block is used to generate the
data acknowledge signals for the chip select address space
selected by the PADEC. The access speed of peripheral IC
devices is generally slower than that of the main process-
ing unit (MPU). To adjust this speed gap between them,
the user is allowed to insert from 0 to 4 wait cycles into
each address cycle. The number of wait cycles to be in-
serted is programmable. In addition, the user is permitted
to disable the DTACK (active low) generator so that it can
be generated by an external device.
PINTH (Programmable Interrupt Handler)
The PINTH functional block is used as an interrupt han-
dler to output the vectored numbers corresponding to the
68000 MPU vectored interrupts. Each of the IPL levels and
vectored numbers for internal block/external interrupt re-
quests is programmable.
RCHIPIF (LC8951 RCHIP Interface)
The RCHIPIF functional block is used to provide the inter-
face between the 68000 MPU and the LC8951 RCHIP. This
interface enables direct communication between them. As
a result, status data, data signal and error bit information
can be directly communicated between them.
ADPCMIF (LC8955 Interface)
The ADPCMIF functional block is used to provide the in-
terface between the 68000 MPU and the LC8955. This in-
terface enables direct communication between them. As a
result, data can be directly read from or written to internal
registers of the LC8955 from the MPU.
TICKGEN (Tick Generator)
The TICKGEN functional block is used to generate timer
interrupt clocks for a real-time operating system. The timer
interrupt clocks can be generated by dividing the system
clock or selecting an external input clock. As a result, the
tick can be set independent of the system clock frequency.
MOUSEIF (Serial Mouse Interface)
The MOUSEIF functional block is used as the data receive
port for a standard serial mouse. The communication pa-
rameters such as parity bit, stop bit, data bits and baud rate
can be changed by software. In addition, the interrupt sig-
nal generation timing can be set to either 3-byte or 1-byte
intervals. Therefore, this functional block can be used as a
general-purpose receive serial port as well as the mouse
serial port. Note that the mouse transmits an XY coordi-
nate value to the serial port in 3-byte packets.
MPDMAC (Micro-Programmable DMA Controller)
The MPDMAC functional block is used as the DMA con-
troller. With this controller, the operation can be pro-
grammed by a 16-instruction micro code. These instruc-
tions can be programmed to support data read operations
from the LC8951 (RCHIP), data write operations to the
LC8955 as well as the basic transfer operations with
memory. In addition, they include rather complicated in-
structions to enable data comparison, logical operation and
conditional jump operations. Therefore, this controller
block can be used as a sub-CPU to enable intelligent pro-
cessing, and to reduce the load on the MPU.
BERRGEN (Bus Error Generator)
The BERRGEN functional block is used to generate the
bus error signal for the 68000 MPU when no AS (active
low) signal is detected. There are four AS signal inactive
periods. The user is allowed to select one from the four to
best suit the application system in mind.
CLKDIV (Clock Divider Circuit)
The CLKDIV function block is used to generate the MPU
clock with 1: 1 duty cycle by dividing the master clock by
2.
No.3411–8/9
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