概觀
CS6257 is a 32-Bit MCU with embedded Flash designed
for motor control applications. The CPU is MIPS-X core
with enhanced DSP instructions and accelerator and can
run up to 125MHz. There are on-chip 64KB SRAM and
embedded 128KB Flash memory. The flash memory is
accessed through a cache controller which is shared
with external SPI flash memory controller. This external
SPI flash memory can be used to further expand the
program and data memory space. Combining the CPU
and flexible memory structure, CS6257 provide a
powerful computing platform and execution unit for
various motor control requirements.
The motor controller consists of a 16-bit programmable
counter which drives three synchronous 16-bit PWM
channels. The counter also includes six pointers to
trigger ADC synchronization and software interrupt.
Each channel of PWM has two outputs that control
upper and lower driver of the motor winding. There are
flexible controls of these outputs including polarity,
default drive level, as well as dead time control of rising
and falling edges individually. The overload detection
and protection circuits can accept external inputs or the
output of analog comparators for activation of protection.
Coupled closely with the motor controller are a fast 12-
Bit pipeline ADC. The ADC has a conversion rate of
1Mbps and has 3 channels of Track and Hold as front-
end. There are also 3 pairs of analog comparators with
programmable threshold that can be used for current
and phase detection of the drive currents.
Other on-chip peripherals include another 8-channel 12-
Bit SAR ADC, I2C controller, UART/LIN interface, and
SPI controller, and CAN controller. These interfaces
share the connection with GPIO ports of the CPU. The
GPIO ports also can be used for external interrupt.
CS6257 also includes power-on reset circuits and low-
voltage detecting circuit. The embedded flash controller
has built-in protection to prevent data and program loss
by accidents. It also handles code security to protect
unauthorized access of the contents of the embedded
flash. An E-JTAG interface is used for debug and ISP
purpose. CS6257 requires only single 5Vsupply with a
built-in 1.8V regulator for core logic. The regulator
requires an external NPN transistor for reducing the
power dissipation on chip.
The IDE (Integrated Development Environment) includes
Debugger, C-compiler, Assembler and Linker. The
library also include real time OS (uC-OS and NNOS) and
binary functional calls as well as communication stacks.