XE8805AMI028LF Semtech, XE8805AMI028LF Datasheet - Page 43

• Manufacturer Part Number: XE8805AMI028LF
• Description: IC DAS 16BIT FLASH 8K MTP 64LQFP
• Manufacturer: Semtech

Specifications of XE8805AMI028LF

• Applications: Sensing Machine
• Core Processor: RISC
• Program Memory Type: FLASH (22 kB)
• Controller Series: XE8000
• Ram Size: 512 x 8
• Interface: UART, USRT
• Number Of I /o: 24
• Voltage - Supply: 2.4 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Supply Voltage Range: 2.4V To 5.5V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 64
• For Use With: XE8000MP - PROG BOARD AND PROSTART2 CARD
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.1 Features
7.2 Overview
The XE8805 chips can work on different clock sources (RC oscillator, quartz oscillator and external clock). The
clock generator block is in charge of distributing the necessary clock frequencies to the circuit. Figure 7-1
represents the functionality of the clock block.
The internal RC oscillator drives the high prescaler. This prescaler generates frequency divisions down to 1/256 of
its input frequency. A 32kHz clock is generated by enabling the quartz oscillator (if present in the product) or by
selecting the appropriate tap on the high prescaler. The low prescaler generates clock signals from 32kHz down to
1Hz. The clock source for the CPU can be selected from the RC oscillator, the external clock or the 32kHz clock.
7.3 Register map
© Semtech 2006
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•
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3 available clock sources (RC oscillator, quartz oscillator and external clock).
2 divider chains: high-prescaler (8 bits) and low-prescaler (15 bits).
CPU clock disabling in halt mode.
7
6
5
4
3
2
1
0
7-4
3
2
1
0
7-1
0
pos.
pos.
pos.
CpuSel
Extclk
EnExtClock
BiasRc
ColdXtal
ColdRC
EnableXtal
EnableRc
--
RCOnPA0
DebFast
OutputCkXtal
OutputCpuCk
--
ResPre
RegSysClock
RegSysMisc
RegSysPre0
rw
r
rw
rw
r
r
rw
rw
r
rw
rw
rw
rw
r
w1
r0
rw
rw
rw
Table 7-1: RegSysClock register
Table 7-2: RegSysMisc register
Table 7-3: RegSysPre0 register
0 resetsleep
0 resetcold
0 resetcold
1 resetcold
1 resetsleep
1 resetsleep
0 resetsleep
1 resetsleep
0000
0 resetsleep
0 resetsleep
0 resetsleep
0 resetsleep
0000000
0
Reset
Reset
reset
7-2
Select speed for cpuck, 0=RC, 1=xtal or
external clock
External clock detected, 1=available
Enable for external clock, 1=enabled
Enable Rcbias (reduces start-up time of RC).
Xtal in start phase
RC in start phase
Enable Xtal oscillator, 0=disabled, 1=enabled
Enable RC oscillator, 0=disabled, 1=enabled
Unused
Start RC on PA[0], 0=disabled, 1=enabled
Debouncer clock speed, 0=256Hz, 1=8kHz
Output Xtal Clock on PB[3], 0=disabled,
1=enabled if EnXtal=1 else PB[3]=0
Output CPU clock on PB[2], 0=disabled,
1=enabled
Unused
Write 1 to reset low prescaler, but always
reads 0
Function
Function
function
XE8805/05A
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