CY7C68013A, CY7C68014A

CY7C68015A, CY7C68016A

10.5 PORTC Strobe Feature Timings

The RD# and WR# are present in the 100-pin version and the 128-pin package. In these 100-pin and 128-pin versions, an 8051 control bit can be set to pulse the RD# and WR# pins when the 8051 reads from or writes to PORTC. This feature is enabled by setting PORTCSTB bit in CPUCS register.

The RD# and WR# strobes are asserted for two CLKOUT cycles when PORTC is accessed.

The WR# strobe is asserted two clock cycles after PORTC is updated and is active for two clock cycles after that, as shown in Figure 15.

As for read, the value of PORTC three clock cycles before the assertion of RD# is the value that the 8051 reads in. The RD# is pulsed for 2 clock cycles after 3 clock cycles from the point when the 8051 has performed a read function on PORTC.

The RD# signal prompts the external logic to prepare the next data byte. Nothing gets sampled internally on assertion of the RD# signal itself, it is just a prefetch type signal to get the next data byte prepared. So, using it with that in mind easily meets the setup time to the next read.

The purpose of this pulsing of RD# is to allow the external peripheral to know that the 8051 is done reading PORTC and the data was latched into PORTC three CLKOUT cycles before asserting the RD# signal. After the RD# is pulsed, the external logic can update the data on PORTC.

Following is the timing diagram of the read and write strobing function on accessing PORTC. Refer to Section 10.3 and Section 10.4 for details on propagation delay of RD# and WR# signals.

Figure 15. WR# Strobe Function when PORTC is Accessed by 8051

tCLKOUT

CLKOUT

PORTC IS UPDATED

 

tSTBL

tSTBH

 

 

 

 

 

 

 

WR#

Figure 16. RD# Strobe Function when PORTC is Accessed by 8051

tCLKOUT

CLKOUT

8051 READS PORTC

DATA MUST BE HELD FOR 3 CLK CYLCES

DATA CAN BE UPDATED BY EXTERNAL LOGIC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

tSTBL

 

tSTBH

 

 

 

 

 

 

 

 

 

 

 

 

RD#

Document #: 38-08032 Rev. *L

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Cypress CY7C68015A, CY7C68013, CY7C68016A manual Portc Strobe Feature Timings, WR# Strobe Function when Portc is Accessed by
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CY7C68016A, CY7C68014A, CY7C68015A, CY7C68013 specifications

The Cypress CY7C68013, CY7C68015A, CY7C68014A, and CY7C68016A are part of Cypress Semiconductor's EZ-USB family of microcontrollers, known for their high performance and flexibility in USB applications. These devices are primarily used for USB interfacing and have gained popularity in various industries due to their robust features and capabilities.

One of the main features of the CY7C68013 is its Dual FIFO architecture, allowing for efficient data transfer between USB and the system memory. This feature optimizes throughput and reduces CPU overhead, making it an excellent choice for applications that require high-speed data exchange, such as video streaming, data acquisition, and industrial automation. The device is equipped with a USB 2.0 interface which supports full-speed operation at 12 Mbps, ensuring compatibility with a wide range of USB devices.

The CY7C68015A, a similar variant, offers additional memory options, providing users with the flexibility to select the necessary capacity for their specific applications. This part is particularly useful in scenarios that demand more users or higher data storage, making it ideal for complex USB peripherals like printers and multifunction devices. Moreover, it includes a unique capability of upgradeable firmware, ensuring that the device remains relevant and functional as technology evolves.

In contrast, the CY7C68014A stands out with its support for isochronous data transfers, making it suitable for real-time applications that require timely data delivery. This is particularly important in audio and video applications where delays can impact performance. The device incorporates advanced power management features, allowing it to operate efficiently both in low and high-power modes.

Lastly, the CY7C68016A integrates enhanced security features, positioning it as an ideal choice for applications that require data integrity and protection against unauthorized access. It supports various encryption standards and provides secure boot capabilities, making it suitable for secure environments such as financial transactions and sensitive data processing.

In summary, the CY7C68013, CY7C68015A, CY7C68014A, and CY7C68016A microcontrollers offer a versatile suite of features that cater to a wide array of USB applications. Their design emphasizes performance, flexibility, and security, making them essential components in today's rapidly evolving technology landscape. Whether in consumer electronics, industrial automation, or specialized applications, these devices provide the reliability and efficiency that engineers and developers require.
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