Write codes of the vertical microinstructions for Basic Computer that increment the value of the data register by one (DR = DR+1). You can use several microinstructions.
时间: 2023-06-15 17:06:58 浏览: 54
Here are the vertical microinstructions for Basic Computer that increment the value of the data register by one:
1. MAR <- 0
2. MBR <- DR
3. AC <- MBR + 1
4. DR <- AC
5. PC <- PC + 1
Explanation:
1. Load the memory address register (MAR) with the value 0, indicating we want to access the memory location where the data register (DR) is located.
2. Load the memory buffer register (MBR) with the current value of the DR.
3. Add 1 to MBR using the accumulator (AC).
4. Store the new value back into the data register (DR).
5. Increment the program counter (PC) to the next instruction.
相关问题
can you show me the codes of the l2 forwarding by DPDK
是的,我可以为您提供 DPDK 实现 L2 转发的代码示例。以下是一份使用 DPDK 实现 L2 转发的代码:
```
#include <stdio.h>
#include <stdint.h>
#include <rte_eal.h>
#include <rte_ethdev.h>
#include <rte_mbuf.h>
#define NUM_MBUFS 8191
#define MBUF_CACHE_SIZE 250
#define BURST_SIZE 32
static const struct rte_eth_conf port_conf_default = {
.rxmode = {
.max_rx_pkt_len = ETHER_MAX_LEN,
},
};
int main(int argc, char *argv[]) {
int ret;
uint16_t nb_ports;
uint16_t portid;
struct rte_mbuf *pkts_burst[BURST_SIZE];
unsigned i, j;
ret = rte_eal_init(argc, argv);
if (ret < 0)
rte_exit(EXIT_FAILURE, "Invalid EAL parameters\n");
nb_ports = rte_eth_dev_count();
if (nb_ports == 0)
rte_exit(EXIT_FAILURE, "No Ethernet ports\n");
for (i = 0; i < nb_ports; i++) {
portid = i;
ret = rte_eth_dev_configure(portid, 1, 1, &port_conf_default);
if (ret < 0)
rte_exit(EXIT_FAILURE, "Cannot configure device: err=%d, port=%u\n",
ret, portid);
ret = rte_eth_dev_start(portid);
if (ret < 0)
rte_exit(EXIT_FAILURE, "Cannot start device: err=%d, port=%u\n",
ret, portid);
rte_eth_promiscuous_enable(portid);
}
while (1) {
for (i = 0; i < nb_ports; i++) {
portid = i;
const uint16_t nb_rx = rte_eth_rx_burst(portid, 0,
pkts_burst, BURST_SIZE);
if (unlikely(nb_rx == 0))
continue;
for (j = 0; j < nb_rx; j++) {
struct rte_mbuf *m = pkts_burst[j];
rte_eth_tx_burst(portid ^ 1, 0, &m, 1);
rte_pktmbuf_free(m);
}
}
}
return 0;
}
```
请注意,这仅仅
can you show me the codes of the L2 forwarding feature implement by P4
很抱歉,作为一个语言模型,我不能提供完整的代码。然而,我可以告诉您P4语言如何实现L2转发功能。
L2转发功能的实现包括以下步骤:
1. 定义数据包头,其中包含L2地址(例如MAC地址)。
2. 使用控制器程序计算数据包的目的地址。
3. 使用table表和action操作转发数据包到目的地。
以下是一个简化的P4代码示例,该代码演示了如何实现L2转发功能:
```
header_type ethernet_t {
fields {
dstAddr : 48;
srcAddr : 48;
etherType : 16;
}
}
struct l2_forward_metadata_t {
bit<9> port;
}
parser parse_ethernet(packet_in packet,
out ethernet_t ethernet,
out l2_forward_metadata_t l2_forward_metadata) {
// Extract the Ethernet header and populate the header instance
var bit<16> pktLen = packet.extract(ethernet);
l2_forward_metadata.port = packet.getParserState().ingress_port;
return pktLen;
}
table l2_fwd {
reads {
ethernet.dstAddr : l2_dst;
l2_forward_metadata.port : l2_in_port;
}
actions {
set_dst_port(port : l2_out_port);
}
size : 4096;
}
action set_dst_port(bit<9> port) {
standard_metadata.egress_spec = port;
}
control ingress {
apply(parse_ethernet) {
l2_fwd.apply(ethernet.dstAddr, l2_forward_metadata.port);
}
}
```
希望这对您有所帮助!