psd813f3 STMicroelectronics, psd813f3 Datasheet - Page 33

• Manufacturer Part Number: psd813f3
• Description: Flash In-system Programmable Isp Peripherals For 8-bit Mcus
• Manufacturer: STMicroelectronics

PLDS
The PLDs bring programmable logic functionality
to the PSD. After specifying the logic for the PLDs
using the PSDabel tool in PSDsoft Express, the
logic is programmed into the device and available
upon Power-up.
The PSD contains two PLDs: the Decode PLD
(DPLD), and the Complex PLD (CPLD). The PLDs
are briefly discussed in the next few paragraphs,
and in more detail in the section entitled
PLD (DPLD), page 35
Complex
13., page 34
The DPLD performs address decoding for Select
signals for internal components, such as memory,
registers, and I/O ports.
The CPLD can be used for logic functions, such as
loadable counters and shift registers, state ma-
chines, and encoding and decoding logic. These
logic functions can be constructed using the 16
Output Macrocells (OMC), 24 Input Macrocells
(IMC), and the AND Array. The CPLD can also be
used to generate External Chip Select (ECS0-
ECS2) signals.
The AND Array is used to form product terms.
These product terms are specified using PSDabel.
An Input Bus consisting of 73 signals is connected
to the PLDs. The signals are shown in Table 14.
The Turbo Bit in PSD
The PLDs in the PSD can minimize power con-
sumption by switching off when inputs remain un-
changed for an extended time of about 70ns.
Resetting the Turbo Bit to '0' (Bit 3 of PMMR0) au-
tomatically places the PLDs into standby if no in-
puts are changing. Turning the Turbo mode off
increases propagation delays while reducing pow-
er consumption. See the section entitled
MANAGEMENT, page 62
Bit.
PLD
shows the configuration of the PLDs.
(CPLD), page
and the section entitled
on how to set the Turbo
36.
PSD813F2, PSD833F2, PSD834F2, PSD853F2, PSD854F2
POWER
Decode
Figure
Additionally, five bits are available in PMMR2 to
block MCU control signals from entering the PLDs.
This reduces power consumption and can be used
only when these MCU control signals are not used
in PLD logic equations.
Each of the two PLDs has unique characteristics
suited for its applications. They are described in
the following sections.
Table 14. DPLD and CPLD Inputs
Note: 1. The address inputs are A19-A4 in 80C51XA mode.
MCU Address Bus
MCU Control Signals
Reset
Power-down
Port A Input
Macrocells
Port B Input
Macrocells
Port C Input
Macrocells
Port D Inputs
Page Register
Macrocell AB
Feedback
Macrocell BC
Feedback
Secondary Flash
memory Program
Status Bit
Input Source
1
MCELLBC.FB7-
MCELLAB.FB7-
CNTL2-CNTL0
PGR7-PGR0
Input Name
Ready/Busy
PC7-PC0
PD2-PD0
PB7-PB0
PA7-PA0
A15-A0
RST
PDN
FB0
FB0
Number
Signals
33/110
16
of
3
1
1
8
8
8
3
8
8
8
1