CY8C34_1105 Datasheet, PDF (43/127 Pages) Cypress Semiconductor – Programmable System-on-Chip (PSoC) DC to 50 MHz operation

PSoC^® 3: CY8C34 Family
Data Sheet
7.2.2 Datapath Module
The datapath contains an 8-bit single cycle ALU, with associated compare and condition generation logic. This datapath block is
optimized to implement embedded functions, such as timers, counters, integrators, PWMs, PRS, CRC, shifters and dead band
generators and many others.
Figure 7-8. Datapath Top Level
PHUB System Bus
R/W Access to All
Registers
F1
Input from
Programmable
Routing
Input
Muxes
6
FIFOs
F0
D1
Data Registers
Output
Muxes
A0
Output to
A1
Programmable
D0
6 _Routing
D1
D0
To/From
To/From
Previous
Chaining
Next
A1
Datapath
Datapath
Accumulators
A0
PI
Parallel Input/Output
(To/From Programmable Routing)
PO
ALU
Shift
Mask
7.2.2.1 Working Registers
The datapath contains six primary working registers, which are
accessed by CPU firmware or DMA during normal operation.
Table 7-1. Working Datapath Registers
Name
Function
A0 and A1 Accumulators
D0 and D1 Data Registers
F0 and F1 FIFOs
Description
These are sources and sinks for
the ALU and also sources for the
compares.
These are sources for the ALU
and sources for the compares.
These are the primary interface to
the system bus. They can be a
data source for the data registers
and accumulators or they can
capture data from the accumu-
lators or ALU. Each FIFO is four
bytes deep.
7.2.2.2 Dynamic Datapath Configuration RAM
Dynamic configuration is the ability to change the datapath
function and internal configuration on a cycle-by-cycle basis,
under sequencer control. This is implemented using the 8-word
× 16-bit configuration RAM, which stores eight unique 16-bit
wide configurations. The address input to this RAM controls the
sequence, and can be routed from any block connected to the
UDB routing matrix, most typically PLD logic, I/O pins, or from
the outputs of this or other datapath blocks.
ALU
The ALU performs eight general purpose functions. They are:
„ Increment
„ Decrement
„ Add
„ Subtract
„ Logical AND
Document Number: 001-53304 Rev. *L
Page 43 of 127