August 17, 2005
Document No. 38-12036 Rev. *A
2
CY8C95xx Preliminary Data Sheet
Overview
There are 4 (CY8C9520), 8 (CY8C9540) or 16 (CY8C9560)
independently configurable 8-bit PWMs. These PWMs are
denoted as PWM0-PWM15. Each PWM can be clocked by one
of six available clock sources.
Architecture
The figure titled “Top Level Block Diagram” on page 1 illustrates
the device block diagram. The main blocks include the control
unit, PWMs, EEPROM and I/O ports. The control unit executes
commands received from the I2C bus and transfers data
between other bus devices and the master device.
The on-chip EEPROM can be separated conventionally into two
regions. The first region is designed to store data and is avail-
able for byte-wide read/writes via the I2C bus. It is possible to
prevent write operations by setting the WD pin to high. All
EEPROM operations can be blocked by configuration register
settings. The second region allows the user to store the port
and PWM default settings using special commands. These
defaults will be automatically reloaded and processed after
device power-on.
The number of I/O lines and PWM sources is presented in the
following table.
There are four pins on GPort 2 and three on GPort 1 that can be
used as general purpose I/O or EEPROM Write Disable (WD)
and I2C-address input (A1-A6), depending on configuration set-
tings.
The figure titled “Logical Structure of the I/O Port” shows the
single port logical structure. The Port Drive Mode register gives
the option to select one of seven available modes for each pin
separately: pulled-up/-down, open drain high/low, strong drive
fast/slow, or high-impedance. By default these configuration
registers store values setting I/O pins to pulled-up. The Invert
register allows for inversion of the logic of the Input registers
separately for each pin. The Select PWM register allows pins to
be assigned as PWM outputs. All of these configuration regis-
ters are read/writable using corresponding commands in the
multi-port device.
Figure 1-2. Logical Structure of the I/O Port
The Port Input and Output registers are separated. When the
Output register is written, the data is sent to the external pins.
When the Input register is read, the external pin logic levels are
captured and transferred. As a result, the read data can be dif-
ferent from written Output register data. This allows for imple-
mentation of a quasi-bidirectional input-output mode, when the
corresponding binary digit is configured as pulled-up/down out-
put.
Each GPort has an Interrupt Mask register and an Interrupt Sta-
tus register. Each high bit in the Interrupt Status register signals
that there has been a change in the corresponding input line
since the last read of that Interrupt Status register. The Interrupt
Status register is cleared after each read. The Interrupt Mask
register enables/disables activation of the INT line when input
levels are changed. Each high in the Interrupt Mask register
masks (disables) an interrupt generated from the corresponding
input line.
Applications
Each GPIO pin can be used to monitor and control various
board-level devices, including LEDs and system intrusion
detection devices.
The on-board EEPROM can be used to store information such
as error codes or board manufacturing data for read-back by
application software for diagnostic purposes.
Table 1-1. GPIO Availability
Port
CY8C9520
CY8C9540
CY8C9560
GPort 0
8 bit
8 bit
8 bit
GPort 1
5-8 bit∗
5-8∗ bit
5-8 bit∗
GPort 2
0-4 bit∗
0-4∗ bit
0-4 bit∗
GPort 3
-
8 bit
8 bit
GPort 4
-
8 bit
8 bit
GPort 5
-
4 bit
8 bit
GPort 6
-
-
8 bit
GPort 7
-
-
8 bit
PWMs
4
8
16
* This port contains configuration-dependant GPIO lines or A1-A6 and WD lines.
GPortx
7 Drive Mode
Registers
DriveMode
Pull-Up
DriveMode
High-Z
Interrupt
Status
Interrupt
Mask
Pin Direction
Inversion
Input Register
Select PWM
Output
Register
8 Bit I/O
Data
PWMs
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