Using ADS1.2 and JLINK V8 to build ARM7 development platform-EEWORLD

Collect

Hardware resources: a circuit board with ARM7 (LPC2119) as the core, Jlink v8 emulator, LONGWEIPS-305DM DC regulated power supply, laptop (installed with Windows 7 Ultimate)

Software resources: ADS1.2 Jlink v8 driver Setup_JLinkARM_V408i

Recently, I need to use the LPC2119 chip, but I don't have an emulator for this chip. I checked online and found that the cheapest emulator AK100 produced by Zhou Ligong Company on Taobao costs 1.8K. I am short of money. LZ suddenly remembered that I used the Jlink v8 emulator when I used ADS1.2 to develop S3C2440. Can this emulator be used with the LPC2119 chip? So I quickly asked Baidu and found out that Jlink v8 supports the LPC2119 chip. I was very happy and started to try it immediately.

Since the download slot on my existing circuit board is already soldered as a single-row 8-pin slot, it cannot be used with my existing Jlink v8 2*4 slot, but the adapter board of the Jlink v8 emulator has 2*7, 2*10 and other pins. So I took the existing DuPont wires from the pins of the adapter board, and the DuPont wires were also plugged into a row of pins, and the wires led out from the adapter board and the circuit board slots matched one by one (nTRST, TDI, TMS, TCK, RTCK, TDO, nRST, VDD). After the wires were properly connected, the circuit board was powered on, and the ADS policy DEBUG was started (the prerequisite is that the JLINK driver is installed and configured, you can search for the Jlink v8 user manual on Baidu, which has detailed operation tutorials), and an error was reported, and low voltage was always displayed. This confused me. I checked whether the wires were not connected properly and whether the chip power supply was normal.... I searched Baidu for a lot of information but there was no relevant explanation. I had no choice but to carefully study the hardware structure of Jlink v8, and test the voltage of each port to see if it was normal. Finally, I found that there was a Vref on Jlink v8 that was always low, and according to the data sheet, it should be connected to Vdd as 3.3v, so I connected Vref to Vdd3.3v by flying a wire, and the problem was solved... But there was a question left, why didn't I report an error when I used Jlink v8 to burn the S3C2440 program before??

When I finished compiling the program and downloaded it to the target board, hey, I encountered another problem. I couldn't enter the interrupt. I was so annoyed that I quickly looked for the reason. First, I checked whether the initialization program related to the interrupt was correct and whether the interrupt was masked. If there was no problem, I checked whether the interrupt flag in the memory was set. Strangely, my interrupt flag was set, but I couldn't enter the interrupt service program. I checked other registers related to the interrupt and found that the CPSR register was abnormal. This was related to the startup code of ARM7. After searching the Internet, I found that there were two possible reasons for the inability to trigger the interrupt.

1. Please pay attention to your program debugging mode selection. If you select DebugInFlash or RelInFlash, the program entry address should be: 0x00000000; if you select DebugInRam, the program entry address should be: 0x40000000.

The project template I downloaded from Zhou Ligong has the entry address set correctly, so this reason is ruled out.

2. The stack initialization function is incorrectly set in the Startup.s file

The code in the original project template I downloaded is as follows

InitStack

MOV R0, LR

;Build the SVC stack

; Set management mode stack

MSR CPSR_c, #0xd3

LDR SP, StackSvc

;Build the IRQ stack

; Set up interrupt mode stack

MSR CPSR_c, #0xd2

LDR SP, StackIrq

;Build the FIQ stack

; Set up fast interrupt mode stack

MSR CPSR_c, #0xd1

LDR SP, StackFiq

;Build the DATAABORT stack

; Set up the abort mode stack

MSR CPSR_c, #0xd7

LDR SP, StackAbt

;Build the UDF stack

; Set up undefined mode stack

MSR CPSR_c, #0xdb

LDR SP, StackUnd

;Build the SYS stack

; Set up system mode stack

MSR CPSR_c, #0xdf

LDR SP, =StackUsr

MOV PC, R0

The last sentence is MSR CPSR_c,#0xdf. This is the problem, the IRQ interrupt is blocked. I have returned the assembly code to the teacher, so I won't make fun of it here. For the interpretation of the startup code, please refer to: http://blog.chinaunix.net/uid-22124213-id-403007.html

Change the above code to the following: