GD32F20x User Manual
33
Figure 1-1.
Cortex™-M3 block diagram
ETM
CM3Core
Istruction
Data
NVIC
Interrupts
Sleep
Debug
MPU
FPB
DWT
ITM
Cotex-M3
TPIU
Trigger
APB
i/f
Bus
Matrix
Private Peripheral Bus
(internal)
AHB-AP
SW/
SWJ-DP
SW/
JTAG
INTNMI
INTISR[239:0]
SLEEPING
SLEEPDEEP
ROM
Table
Private
Peripheral
Bus
(external)
Trace port
(serial wire
or multi-pin)
I-code bus
D-code bus
System bus
1.2.
System architecture
The system architecture of the GD32F20x series is shown in the following figure. The AHB
matrix based on AMBA 3.0 AHB-LITE is a multi-layer AHB, which enables parallel access
paths between multiple masters and slaves in the system. There are seven masters on the
AHB matrix, including ICode, DCode, system bus of the Cortex™-M3 core, DMA0, DMA1,
Ethernet and TLI. The ICode bus is the instruction bus and also used for vector fetches from
the Code region (0x0000 0000 ~ 0x1FFF FFFF) to the Cortex™-M3 core. The DCode bus is
used for loading/ storing data and also for debug access of the Code region. Similarly, the
System bus is used for instruction/vector fetches, data loading/storing and debugging access
of the system regions. The System regions include the internal SRAM region, the external
memory region and the Peripheral region. The AHB matrix consists of eight slaves, including
ICode and DCode interfaces of the flash memory controller, internal SRAM0, SRAM1, SRAM2,
external memory controller, system AHB1 and AHB2.
The AHB1 bus is connected to almost all the AHB peripherals, it includes two AHB-to-APB
bus bridges which provide full synchronous connections between the system AHB and the
two APB buses. The two APB buses are connected to all the APB peripherals. The maximum
speed of the APB1 bus is 60 MHz, while the APB2 bus can operate at full speed (up to 120
MHz depending on the device).
These are interconnected using a multilayer AHB bus architecture as shown in
Summary of Contents for GD32F20 Series
Page 191: ...GD32F20x User Manual 191 Bits Fields Descriptions 31 0 TRNDATA 31 0 32 Bit Random data ...
Page 290: ...GD32F20x User Manual 290 conversion is ongoing ...
Page 325: ...GD32F20x User Manual 325 15 0 ALRM 15 0 RTC alarm value low ...
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Page 523: ...GD32F20x User Manual 523 clears AERR bit by writing 0 to it ...