/** * Shifts rows between startRow and endRow n number of rows. * If you use a negative number, it will shift rows up. * Code ensures that rows don't wrap around. * * Calls shiftRows(startRow, endRow, n, false, false); * * <p> * Additionally shifts merged regions that are completely defined in these * rows (ie. merged 2 cells on a row to be shifted). * @param startRow the row to start shifting * @param endRow the row to end shifting * @param n the number of rows to shift */

这是一个函数的注释说明。该函数的作用是将从 startRow 到 endRow 的所有行向下移动 n 行，如果 n 为负数，则将行向上移动。该函数确保行不会超出范围。此外，该函数还会移动那些完全定义在这些行中的合并区域（例如，在要移动的行上合并了两个单元格）。具体实现可能需要考虑边界情况和数据类型等细节。

相关问题

*(unsigned int*)0x40010C00 =((1)<<(4*0))

This line of code is setting a specific bit in a register at memory address 0x40010C00.

The expression `((1)<<(4*0))` shifts the value 1 by 0 bits, which effectively leaves the value unchanged (since any number shifted by 0 bits is still the same number). The result is simply 1.

The outer parentheses are not strictly necessary, but they help clarify the order of operations.

The entire expression is then cast to an `unsigned int*`, which is a pointer to an unsigned integer. This pointer is then dereferenced and assigned the value of 1, effectively setting a specific bit in the register to 1.

The exact meaning of this operation depends on the specific hardware and register being accessed.

Verilog HDL语言实现16*16LED点阵滚动显示英文”red“的程序

下面是一个Verilog HDL程序，用于实现16x16 LED点阵的滚动显示英文单词“red”。该程序使用了一个FPGA板上的16位计数器和一个ROM存储器，其中存储了“red”单词的字模信息。每当计数器增加到特定值时，它将触发一个时钟信号，该信号用于读取ROM存储器并将相应的LED点亮。

module led_matrix(
    input clk,
    input rst,
    output reg [15:0] led_row,
    output reg [15:0] led_col);

reg [3:0] row_counter;
reg [15:0] col_counter;
reg [7:0] rom_data;

parameter delay = 500000; //delay cycles between column shifts

//ROM memory containing "red" word pattern
//each byte represents a column of 8 LEDs
//MSB of each byte represents the top LED in the column
//LSB of each byte represents the bottom LED in the column
//16 bytes in total for 16x16 LED matrix
//pattern for "r"
reg [7:0] rom_r[16] = {
    8'b00000010,
    8'b00000010,
    8'b00000100,
    8'b00001000,
    8'b00001000,
    8'b00001110,
    8'b00001010,
    8'b00001010,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000
};

//pattern for "e"
reg [7:0] rom_e[16] = {
    8'b00000000,
    8'b00000000,
    8'b00111100,
    8'b01000010,
    8'b01000000,
    8'b01111000,
    8'b01000000,
    8'b01000010,
    8'b00111100,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000
};

//pattern for "d"
reg [7:0] rom_d[16] = {
    8'b00000000,
    8'b00000000,
    8'b00011100,
    8'b00100010,
    8'b00100010,
    8'b00100010,
    8'b00100010,
    8'b00100010,
    8'b00011100,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000,
    8'b00000000
};

always @(posedge clk) begin
    if (rst) begin
        row_counter <= 4'd0;
        col_counter <= 16'd0;
        led_row <= 16'd0;
        led_col <= 16'd0;
    end else begin
        if (col_counter >= delay) begin
            col_counter <= 16'd0;
            case (row_counter)
                4'd0: rom_data <= rom_r[col_counter];
                4'd1: rom_data <= rom_e[col_counter];
                4'd2: rom_data <= rom_d[col_counter];
                default: rom_data <= 8'b0;
            endcase
            led_col <= {led_col[14:0], led_row[15]};
            led_row <= {led_row[14:0], rom_data};
            if (row_counter == 4'd15) begin
                row_counter <= 4'd0;
            end else begin
                row_counter <= row_counter + 4'd1;
            end
        end else begin
            col_counter <= col_counter + 1;
        end
    end
end

endmodule

在这个程序中，LED点阵被表示为16x16的矩阵，其中每个元素都是一个LED。程序使用两个16位寄存器来控制LED点阵的输出：led_row和led_col。led_col寄存器用于存储点阵中的列，而led_row寄存器用于存储点阵中的行。

程序使用一个4位计数器来控制行的输出。当计数器增加到15时，它将被重置为0。程序还使用一个16位计数器来控制列的输出。每当计数器增加到特定值（delay）时，它将重置为0，并从ROM存储器中读取相应的字模信息。该程序使用了三个ROM存储器，分别存储字母“r”、“e”和“d”的字模信息。这些字模信息在ROM存储器中以每列8个LED的形式存储，总共有16列，因此需要16个字节来存储每个字母的字模信息。程序通过case语句来选择要读取哪个字母的字模信息，并将该信息存储到rom_data寄存器中。然后，程序使用led_col寄存器将该列左移一位，并使用led_row寄存器将rom_data信息向上移动一行，并将最后一行设置为相应的LED点亮。这样，程序就能够实现16x16 LED点阵的滚动显示英文单词“red”。