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PSD8XXF2/3/4/5
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PSD8XXF2/3/4/5 ARCHITECTURAL OVERVIEW
PSD8xxF2/3/4/5 devices contain several major
functional blocks. Figure 2 shows the architecture
of the PSD8xxF2/3/4/5 device family. The func-
tions of each block are described briefly in the fol-
lowing sections. Many of the blocks perform
multiple functions and are user configurable.
Memory
Each of the memory blocks is briefly discussed in
the following paragraphs. A more detailed discus-
sion can be found in the section entitled “Memory
Blocks“ on page 15.
The 1 Mbit or 2 Mbit (128K x 8, or 256K x 8) Flash
memory is the primary memory of the PSD8xxF2/
3/4/5. It is divided into 8 equally-sized sectors that
are individually selectable.
The optional 256 Kbit (32K x 8) secondary Flash
memory is divided into 4 equally-sized sectors.
Each sector is individually selectable.
The optional SRAM is intended for use as a
scratch-pad memory or as an extension to the
MCU SRAM. If an external battery isconnected to
Voltage Stand-by (VSTBY, PC2), data is retained
in the event of power failure.
Each sector of memory can be located in a differ-
ent address space as defined by the user. The ac-
cess times for all memory types includes the
address latching and DPLD decoding time.
Page Register
The 8-bit Page Register expands the address
range of the MCU by up to 256 times. The paged
address can be used as part of the address space
to access external memory and peripherals, or in-
ternal memory and I/O. The Page Register can
also be used to change the address mapping of
sectors of the Flash memories into different mem-
ory spaces for IAP.
PLDs
The device contains two PLDs, the Decode PLD
(DPLD) and the Complex PLD (CPLD), as shown
in Table 2, each optimized for a different function.
The functional partitioning of the PLDs reduces
power consumption, optimizes cost/performance,
and eases design entry.
Table 2. PLD I/O
The DPLD is used to decode addresses and to
generate Sector Select signals for the PSD8xxF2/
3/4/5 internal memory and registers. The DPLD
has combinatorial outputs. The CPLD has 16 Out-
put Macrocells (OMC) and 3 combinatorial out-
puts. The PSD8xxF2/3/4/5 also has 24 Input
Macrocells (IMC) that can be configured as inputs
to the PLDs. The PLDs receive their inputs from
the PLD Input Bus and are differentiated by their
output destinations, number of product terms, and
macrocells.
The PLDs consume minimal power. The speed
and power consumption of the PLD is controlled
by the Turbo bit in PMMR0 and other bits in the
PMMR2. These registers are set by the MCU at
run-time. There is a slight penalty to PLDpropaga-
tion time when invoking the power management
features.
I/O Ports
The PSD8xxF2/3/4/5 has 27 individually config-
urable I/O pins distributed over the four ports (Port
A, B, C, and D). Each I/O pin can be individually
configured for different functions. Ports can be
configured as standard MCU I/O ports, PLDI/O, or
latched address outputs for MCUs using multi-
plexed address/data buses.
The JTAG pins can be enabled on Port C for In-
System Programming (ISP).
Ports A and B can also be configured as a data
port for a non-multiplexed bus.
MCU Bus Interface
PSD8xxF2/3/4/5 interfaces easily with most 8-bit
MCUs that have either multiplexed or non-multi-
plexed address/data buses. The device is config-
ured to respond to the MCU’s control signals,
which are also used as inputs to thePLDs. For ex-
amples, please see thesection entitled “MCU Bus
Interface Examples“ on page 39.
Table 3. JTAG SIgnals on Port C
JTAG Port
In-System Programming (ISP) can be performed
through the JTAG signals on PortC. This serial in-
terface allows complete programming of the entire
PSD8xxF2/3/4/5 device. A blank device can be
completely programmed. TheJTAG signals (TMS,
TCK, TSTAT, TERR, TDI, TDO) can be multi-
Name
Inputs
Outputs
Product
Terms
Decode PLD (DPLD)
73
17
42
Complex PLD (CPLD)
73
19
140
Port C Pins
JTAG Signal
PC0
TMS
PC1
TCK
PC3
TSTAT
PC4
TERR
PC5
TDI
PC6
TDO