參數(shù)資料
型號(hào)： DS89C450-ENG
廠商： Maxim Integrated Products
文件頁(yè)數(shù)： 22/46頁(yè)
文件大?。?/td> 0K
描述： IC MCU FLASH 64KB 25MHZ 44-TQFP
產(chǎn)品培訓(xùn)模塊： Lead (SnPb) Finish for COTS
產(chǎn)品變化通告： Product Discontinuation 20/Feb/2012
標(biāo)準(zhǔn)包裝： 160
系列： 89C
核心處理器： 8051
芯體尺寸： 8-位
速度： 25MHz
連通性： EBI/EMI，SIO，UART/USART
外圍設(shè)備： 電源故障復(fù)位，WDT
輸入/輸出數(shù)： 32
程序存儲(chǔ)器容量： 64KB（64K x 8）
程序存儲(chǔ)器類型： 閃存
RAM 容量： 1K x 8
電壓 - 電源 (Vcc/Vdd)： 4.5 V ~ 5.5 V
振蕩器型： 外部
工作溫度： -40°C ~ 85°C
封裝/外殼： 44-TQFP
包裝： 托盤
DS89C430/DS89C450 Ultra-High-Speed Flash Microcontrollers
29 of 46
Page Mode, External Memory Cycle
Page mode retains the basic circuitry requirement for an original 8051 external memory interface, but alters the
configuration of P0 and P2 for the purposes of address output and data I/O during external memory cycles.
Additionally, the functions of ALE and PSEN are altered to support this mode of operation.
Setting the PAGEE (ACON.7) bit to logic 1 enables page mode. Clearing the PAGEE bit to logic 0 disables the
page mode and the external bus structure defaults to the original 8051 expanded bus configuration (nonpage
mode). The DS89C430 supports page mode in two external bus structures. The logic value of the page-mode-
select bits in the ACON register determines the external bus structure and the basic memory cycle in number of
system clocks. Table 6 summarizes this option. The first three selections use the same bus structure but with
different memory cycle time. Setting the select bits to 11b selects another bus structure. Write access to the ACON
register requires a timed access.
Table 6. Page Mode Select
CLOCKS PER MEMORY CYCLE
PAGES1:PAGES0
PAGE-HIT
PAGE-MISS
EXTERNAL BUS STRUCTURE
00
1
2
P0: Primary data bus.
P2: Primary address bus, multiplexing both the upper byte and
lower byte of address.
01
2
4
P0: Primary data bus.
P2: Primary address bus, multiplexing both the upper byte and
lower byte of address.
10
4
8
P0: Primary data bus.
P2: Primary address bus, multiplexing both the upper byte and
lower byte of address.
11
2
4
P0: Lower address byte.
P2: The upper address byte is multiplexed with the data byte.
Note: This setting affects external code fetches only; accessing
the external data memory requires four clock cycles, regardless
of page hit or miss.
The first page mode’s (page mode 1) external bus structure uses P2 as the primary address bus, (multiplexing both
the most significant byte and least significant byte of the address for each external memory cycle) and P0 is used
as the primary data bus. During external code fetches, P0 is held in a high-impedance state by the processor. Op
codes are driven by the external memory onto P0 and latched at the end of the external fetch cycle at the rising
edge of PSEN. During external data read/write operations, P0 functions as the data I/O bus. It is held in a high-
impedance state for external reads from data memory and driven with data during external writes to data memory.
A page miss occurs when the most significant byte of the subsequent address is different from the last
address. The external memory machine cycle can be 2, 4, or 8 system clocks in length for a page miss.
A page hit occurs when the most significant byte of the subsequent address does not change from the last
address. The external memory machine cycle can be 1, 2, or 4 system clocks in length for a page hit.
During a page hit, P2 drives Addr [0–7] of the 16-bit address, while the most significant address byte is held in the
external address latches. PSEN, RD, and WR strobes accordingly for the appropriate operation on the P0 data bus.
There is no ALE assertion for page hits.
相關(guān)PDF資料
PDF描述
DS89C440-QNL IC MCU FLASH 32KB 33MHZ 44-PLCC
DS89C440-QNG IC MCU FLASH 32KB 25MHZ 44-PLCC
DS89C440-MNL IC MCU FLASH 32KB 33MHZ 40-DIP
DS89C440-MNG IC MCU FLASH 32KB 25MHZ 40-DIP
DS89C440-ENL IC MCU FLASH 32KB 33MHZ 44-TQFP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
DS89C450-ENG+ 功能描述:8位微控制器 -MCU Ultra-High-Speed Flash MCU RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
DS89C450-ENL 功能描述:8位微控制器 -MCU Ultra-High-Speed Flash MCU RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
DS89C450-ENL+ 功能描述:8位微控制器 -MCU Ultra-High-Speed Flash MCU RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時(shí)鐘頻率:50 MHz 程序存儲(chǔ)器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
DS89C450-K00 功能描述:開(kāi)發(fā)板和工具包 - 8051 RoHS:否 制造商:Silicon Labs 產(chǎn)品:Development Kits 工具用于評(píng)估:C8051F960, Si7005 核心: 接口類型:USB 工作電源電壓:
DS89C450-KIT# 功能描述:開(kāi)發(fā)板和工具包 - 8051 Ultra-High-Speed Flash MCU RoHS:否 制造商:Silicon Labs 產(chǎn)品:Development Kits 工具用于評(píng)估:C8051F960, Si7005 核心: 接口類型:USB 工作電源電壓:
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*