On-Chip A/D and D/A to Support 10.7 MHz IF Interface
Up to 64 Kw of External Program Memory Accessible by
the DSP Core
Bus Interface to Z87010 ADPCM Processor
S
PREAD
P
HONE
Control (AFC) Loop
Buffers
S
PECTRUM
C
ONTROLLER
1
■
DSP Core Acts as Phone Controller
–Zilog-Provided Embedded Transceiver Software to
Control Transceiver Operation and Base StationHandset Communications Protocol
–User-Modifiable Software Governs Telephone
Features
GENERAL DESCRIPTION
The Z87001 /Z87L01 FHSS Cordless Telephone Transceiver/Controller is expressly designed to implement a 900
MHz frequency hopping spread spectrum cordless telephone compliant with US FCC regulations for unlicensed
operation. The Z87001 and Z87L01 are distinct 5V and
3.3V versions, respectively, of the core device. For the
sake of brevity, all subsequent references to the Z87001 in
this document also apply to the Z87L01 unless specifically
noted.
The Z87001 is the ROMless version of the Z87000 Spread
Spectrum Controller IC. Specifically intended to facilitate
user specific software development, the Z87001 can access up to 64 kwords of external program ROM.
■
Static CMOS for Low Power Consumption
■
3.0V to 3.6V, -20 ° C to +70 ° C, Z87L01
4.5V to 5.5V, -20 ° C to +70 ° C, Z87001
■
16.384 MHz Base Clock
The Z87001 supports a specific cordless phone system
design that uses frequency hopping and digital modulation
to provide extended range, high voice quality, and low system costs.
The Z87001 uses a Zilog 16-bit fixed-point two’s complement static CMOS Digital Signal Processor core as the
phone and RF section controller. The Z87001’s DSP core
processor further supports control of the RF section’s frequency synthesizer for frequency hopping and the generation of the control messages needed to coordinate incorporation of the phone’s handset and base station. Additional
on-chip transceiver circuitry supports Frequency Shift Keying modulation/demodulation and multiplexing/demulti-
plexing of the 32 kbps voice data and 4 kbps command
data between handset and base station. The Z87001 provides thirty-two I/O pins, including four wake-up inputs and
two CPU interrupt inputs. These programmable I/O pins allow a variety of user-determined phone features and board
layout configurations. Additionally, the pins may be used
so that phone features and interfaces are supported by an
Codec
Z87010
ADPCM
Processor
Telephone
Line
Interface
Z87001
Spread
Spectrum
Controller
RF Section
Base Station
Figure 1. System Block Diagram of a Z87001/Z87010 Based Phone
optional microcontroller rather than by the Z87001’s DSP
core.
In combination with an RF section designed according to
the system specifications, Zilog’s Z87010/Z87L10 ADPCM
Processor, a standard 8-bit PCM telephone codec and
minimal additional phone circuity, the Z87001 and its embedded software provide a total system solution.
Input V oltage(2) -0.5 V
Output V oltage(3)-0.5 V
Operating
-20+70
+ 0.5V
DD
+ 0.5V
DD
C
Temperature
T
STG
Storage
-65+150
C
Temperature
Notes:
1. Voltage on all pins with respect to GND.
2. Voltage on all inputs WRT VDD
3. Voltage on all outputs WRT VDD
STANDARD TEST CONDITIONS
The electrical characteristics listed below apply for the following standard test conditions, unless otherwise noted.
All voltages are referenced to GND. Positive current flows
into the referenced pins. Standard test conditions are as
follows:
■
■
3.0V < V
4.5V < V
< 3.6V (Z87L01)
DD
< 5.5V (Z87001)
DD
Stresses greater than those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; operation of the device at
any condition above those indicated in the operational sections of these specifications is not implied. Exposure to absolute maximum rating conditions for extended period may
affect device reliability.
Window of time while input signal is applied to sampling capacitor; see next figure.
Uncertainty in sampling time due to random variations such as thermal noise.
Resolution-6-bit
Integral non-linearity-0.51LSB
Differential non-linearity--0.5LSB
Power Dissipation (peak)3570mW
Sample window5-120ns
Bandwidth--2Msps
Supply Range (=AVDD)
Z87L01
Resolution-4-bit
Integral non-linearity-0.250.5LSB
Differential non-linearity-0.251LSB
Settling time (1/2 LSB)--22.5ns
Zero error at 25°C-12mV
Conversion time (input change to output change)141976ns
Power dissipation, 25 pF load1.2
(70°c)
Power dissipation, 25 pF load, Stop mode0.18
(70°c)
20
(40°c)
1.0
(40°c)
24.1
(-20°c)
1.1
(-20°c)
mW
mW
Conversion time (input change to output change)14.519.175.8ns
Rise time (full swing)111571ns
Output slew rate86796V/µs
Output voltage range-0.2 AV
The Z87001 is a peripheral device for the ADPCM Processor. The interface from the Z87001 perspective is composed of an input address bus, a bidirectional data bus,
strobe and read/write input control signals and a
READ CYCLES refer to data transfers from the Z87001 to
the ADPCM Processor.
WRITE CYCLES refer to data transfers from the ADPCM
Processor to the Z87001.
ready/wait output control signal.
Table 11. Read Cycles
Signal NameFunctionDirection
VXADD[2..0]Address BusADPCM Proc. to Z87001
VXDATA[7..0]Data BusBidirectional
VXSTRBStrobe Control SignalADPCM Proc. to Z87001
VXRWBRead/Write Control SignalADPCM Proc. to Z87001
VXRDYBReady Control SignalZ87001 to ADPCM Proc.
Table 12. Write Cycles
No.SymbolParameterMinMaxUnits
8TsASAddress, Read/Write setup time before Strobe falls10ns
9ThSAAddress, Read/Write hold time after Strobe rises3ns
10TaDrSData read access time after Strobe falls30 (1)ns
11ThDrSData read hold time after Strobe rises8.540 (2)ns
12TwSStrobe pulse width20
13TsDwSData write setup time before Strobe rises10ns
14ThDwSData write hold time after Strobe rises3ns
15TaDrRYData read valid before Ready falls22ns
16TdSRYStrobe high after Ready falls0ns
Notes:
1. Requires wait state on ADPCM Processor read cycles
2. Requires no write cycle directly following read cycle on ADPCM Processor
GND. Digital ground.
AVDD. Analog power supply.
AGND. Analog ground.
V
(analog reference). This signal is the reference volt-
REF
age used by the high speed analog comparator to sample
the RX input signal.
RX (analog input). This is the RX IF receive signal from
the RF module, input to the analog comparator and FSK
demodulator. It is internally biased to the V
DC voltage.
REF
The IF signal from the RF module should be AC coupled
to the RX pin.
TX (analog output). This is the IF transmit signal to the RF
module, output from the FSK modulator and transmit 4-bit
D/A converter.
RXSW (output; active high or low programmable). This
pin reflects the programming of the demodulator turn-on
time.
TXSW (output; active high or low programmable). Con-
trol for the receive switch on the RF module. Active during
receive periods.
PAON (output; active high or low programmable). Control for the transmit switch on the RF module. Active during
transmit periods.
RFEON (output; active high or low programmable).
On/off control for the RF module. Active (on) during wake
periods. Inactive (off) during sleep periods on the handset.
CLKOUT (output). Clock output for external ADPCM processor.
CODCLK (output). Clock output for external voice codec.
/RESETB (input, active low). Reset signal.
VXADD[2..0] (input). Address bus controlled by external
ADPCM processor. The Z87001 acts as peripheral of the
Z87010 ADPCM processor.
VXDATA[7..0](input/output). Read/write data bus controlled by external Z87010 ADPCM processor.
VXSTRB (input). Data strobe signal for the VXDATA bus,
controlled by external Z87010.
VXRWB (input). Read/write control for the VXDATA bus,
controlled by external Z87010.
VXRDYB (output, active low). Ready control for the VXDATA bus. This signal is driven high (de-asserted) by the
Z87001 to insert wait states in the Z87010 ADPCM processor accesses.
TEST (input, active high). Main test mode control. Must be
set to GND.
HBSW (input with internal pull-up). Control for handset/base configuration. Must be driven high or not connected for handset, low for base.
P0[15..0] (input/output). General-purpose I/O port. Direction is bit-programmable. Pins P0[3..0],when configured in
input mode, can also be individually programmed as wakeup pins for the Z87001 (wake-up active low; signal internally debounced and synchronized to the bit clock).
RSSI (analog input). Receive signal strength indicator
from RF module, input to the RSSI 8-bit ADC.
PWLV (analog output). Power level control for RF module,
output from the transmit power 4-bit DAC.
SYLE (output). RF synthesizer load enable: latches new
frequency hopping control word of external RF synthesizer. Programmable polarity.
P1[15..0] (input/output).General-purpose I/O port. Direction is bit-programmable. Pins P114 and P115, when configured in input mode, also behave as individually
P0 0WAKEUP0
P0 1WAKEUP1
P0 2WAKEUP2
P0 3WAKEUP3
maskable interrupt pins for the core processor (positive
ANT[1..0] (output). Control for optional antenna diversity
edge-triggered).
on the RF module.
MCLK (input). Master clock input.
The functional partitioning of the Z87001 is shown in Figure 2. The chip consists of a receiver, a transmitter, and
several additional functional blocks.The receiver consists
of the following blocks:
■Receive 1-bit ADC
■Demodulator, including:
–IF Downconverter
–AFC (Automatic Frequency Control)
–Limiter-Discriminator
–Matched Filter
–Bit Synchronizer
–Bit Inversion
–Frame Synchronizer (unique word detector)
–SNR Detector
■Receive Frame Timing Counter
■Receive Buffer and Voice Interface
The Transmitter Consists of the Following Blocks:
■Transmit Buffer and Voice Interface
■Transmit Frame Timing Counter (used on base station
only)
■Modulator, including:
–NCO
–Bit Inversion
■Transmit 4-Bit DAC
In Addition, there are the following Shared Blocks.
■8-Bit ADC for Sampling the Received Signal Strength
Indicator (RSSI)
■DSP Core Processor
■Two 16-Bit General-Purpose I/O Ports
■Z87010 ADPCM Processor Interface
Basic Operation
The transmitter and receiver operate in time-division duplex (TDD): handset and base station transmit and receive
alternately. The TDD duty cycle lasts 4 ms and consists of
the following events:
■At the beginning of the cycle, the frequency is changed
(hopping)
■The base station transmits a frame of 144 bits while the
handset receives
BASE
HANDSET
HOP
Frequency
Hopping
guard time
■The handset then transmits a frame of 148 bits while the
The incoming receive signal at the RX analog input pin is
sampled by a 1-bit analog-to-digital converter at 8.192
MHz.
The receive signal is FSK-modulated (Frequency Shift
Keying) with a carrier frequency of 10.7 MHz (Intermediate
Frequency, or IF). The instantaneous frequency varies between 10.7 MHz plus or minus 32.58 kHz. Since the data
rate is 93.09 kbps, there are 88 samples per data bit. This
oversampled data is further processed by the demodulator
to retrieve the baseband information.
The 1-bit converter is implemented with a fast comparator,
which determines whether the RX signal is larger or smaller than a reference signal (VREF). The Z87001 internally
generates the DC level of both VREF and RX input pins.
The received signal at 10.7 MHz should thus be AC coupled to the RX pin via a coupling capacitor. To ensure accurate operation of the converter, the user should also attach to the VREF pin a network whose impedance
matches the DC impedance seen by the RX pin.
Demodulator
The demodulator includes a two-stage IF downconverter
that brings the sampled receive signal to baseband.
The narrow-band 10.7 MHz receive signal, sampled at
8.192 MHz by the 1-bit ADC, provides a 2.508 MHz useful
image. The first local oscillator used to downconvert this IF
signal is obtained from a Numerically Controlled Oscillator
(NCO) internal to the Z87001, at the nominal frequency of
460 kHz. The resulting signal is thus at 2.048 MHz (= 2.508
MHz - 460 kHz). A second downconversion by a 2.048
MHz signal brings the receive signal to baseband.
The exact frequency of the 460 kHz NCO is slightly adjusted by the Automatic Frequency Control (AFC) loop for exact downconversion of the end signal to the zero frequency. The AFC circuit detects any DC component in the
output of the limiter-discriminator (see below) when receiving a known sequence of data (preamble). This DC component is called the “frequency bias”. The bias estimate
out of the AFC can be read by the DSP processor on every
frame and subsequently filtered. The processor then adds
or subtract this filtered bias to/from the NCO control word
to correct the NCO frequency output.
Rx signal
1-bit
ADC
SSB
460 kHz
+ bias
NCOAFC
2.048 MHz
Figure 2. Demodulator Block Diagram
The main element of the demodulator is its limiter-discriminator. The limiter-discriminator detects the frequency variations (ideally up to ± 32.58 kHz) and converts them to “0”
or “1” information bits. First, the data is processed through
low-pass filters to eliminate high frequency spurious components introduced by the 1-bit ADC. The resulting signal
is then differentiated and fed to a matched filter. In the
matched filter, an integrate-and-dump operation is performed to extract the digital information from its background noise.
The symbol clock is provided by the bit synchronizer. The
bit synchronizer circuit detects 0-to-1 and 1-to-0 transitions
SNR
Filter
Limiter-
Discriminator
Bit
Sync
Frame
Sync
Rx
Buffer
in the incoming data stream in order to synchronize a digital phase-lock loop (DPLL). The PLL output is the recovered bit clock, used to time the receiver on the base station, and both receiver and transmitter on the handset.
To ensure enough transitions in the voice data stream, a
pseudo-random bit inversion operation is performed on the
outgoing voice data. The inversion is then reversed on the
demodulated data.
Since the data is packed in frames sent alternately from
base and handset every 4 ms (TDD), additional synchronization means are necessary. This is realized in a frame
synchronizer, based on detection of a “unique word” following the preamble.
The receiver also features a signal-to-noise ratio detector,
which allows the DSP software to detect noisy channels
and eliminate them from the frequency hopping cycle. The
SNR information is also used by the Z87001 software as a
measure the current range between handset and base station. This information allows the adaptive power control algorithm to provide sufficient output power to the RF transmitter.
Receive Frame Counter
The receive frame counter is responsible to keep track of
time within the frame. It is initialized by the frame synchronizer logic on detection of the unique word. It is then
clocked by the recovered bit clock from the bit synchronizer.
On the base station, the receive frame counter is used as
time base for the receiver. On the handset, it is used as
time base for both receiver and transmitter.
Receive Rate Buffer and Voice Interface
The voice signal is generated at the fixed rate of 32 kips by
the Z87010 processor, and transmitted/received in bursts
of 93.09 kips across the air. Data buffers in the transmitter
and receiver are thus necessary to absorb the rate differences over time. These buffers are called “rate buffers”.
They can store up to 144 data bits and are organized as an
array of 36 4-bit nibbles.
The receive rate buffer stores the received data from the
demodulator. Incoming bits are arranged in 4-bit nibbles
and transferred to successive locations of the rate buffer.
When the last location is reached, transfers resume from
the beginning (circular buffer). The system design guarantees that no buffer overrun nor enduring can occur.
The receive rate buffer can be read by the DSP core processor of the Z87001 or by the Z87010 chip. On the
Z87001 side, the buffer can be read as a random-access
memory: the processor writes the nibble address in an address register and reads the 4-bit data from a data register.
On the Z87010 side, a voice processor interface logic handles the addressing to automatically present the successive voice nibbles to the Z87010 in the order they were received.
Transmit Rate Buffer and Voice Interface
The transmit rate buffer stores the data to be modulated.
The data is sourced from the Z87010 or the Z87001 core
processor. As for the receive rate buffer, the Z87010 sees
a unique pipe to write to, while the Z87001 DSP core accesses the rate buffer as random-access memory. The
modulator reads from the rate buffer as from a circular
buffer.
Transmit Frame Timing Counter
On the handset, transmission does not start until the receiver has synchronized itself to the signal received from
the base station. The transmission timing is based on the
recovered clock. No additional counter is necessary.
On the base station, the situation is different. Transmission
timing is based on a local clock, while the reception’s timing is based on the clock recovered from the incoming received signal. Two counters, respectively clocked by local
and recovered clocks, are necessary to track the transmit
and receive signals.
Note that the receive clock on the base station tracks the
handset’s transmit clock, which is also the handset’s receive clock and tracks the transmit clock of the base station. As a result, receive and transmit clocks of the base
station have exactly the same frequency; only their phases
differ.
Modulator
The modulator consists of a numerically controlled oscillator (NCO) which generates an FSK (Frequency Shift Keying) signal at the carrier frequency of 2.508 MHz. The carrier frequency is shifted plus or minus 32.58 kHz for a “1”
or a “0” data bit. To facilitate conformance to FCC regulations, the transitions from “1” to “0” or vice-versa are
smoothed in order to decrease the amplitude of the side
lobes of the transmit signal. In practice, the jump from one
frequency to the next is performed in several smaller
steps.
The carrier frequency is adjustable by the DSP core processor in order to provide additional frequency adjustment
between base and handset. This is provided in case of a
frequency offset too large for possible correction by the
AFC.
The modulator also includes bit inversion logic as discussed in the receiver section.
The transmit DAC clocks one new NCO value out of the
Z87001 every 8.192 MHz period. Only the 10.7 MHz alias
frequency component of the transmit signal (2.508 + 8.192
MHz image) is filtered, amplified and upconverted to the
900 MHz ISM band by the companion RF module.
Event Trigger Block
The event trigger block is responsible for scheduling the
different events happening at the bit and frame levels. The
event trigger block receives input from the frame counters
as well as the register interface of the DSP core processor.
The event trigger schedules the following events:
NCO
Tx Buffer
Spectral
Shaping
rectly controlled by the Z87001 software through an output
register.
8-Bit ADC for Sampling the Received Signal
Strength Indicator (RSSI)
RSSI information is typically generated from the last stage
of the RF receiver. The RSSI is sampled once per frame
by the 8-bit ADC and used by the Z87001 software to compute the necessary Transmit Power Level voltages.
DSP Core Processor
A DSP core processor constitutes the heart of the Z87001.
The DSP runs the application software which performs the
following functions:
■Start of the 4 ms frame: a synthesizer load enable pulse
is issued on the SYLE pin
■Power-up of the modulator section and transmission of
the frame on handset and base station
■Use of the bit inversion as function of mode
■Power-up of the demodulator section and reception of
the frame on handset and base station
■Control of PAON and TXSW output pins, to be used as
TDD control signals for the T/R switch as well as the
transmitter and receiver chains on the RF module
■Control of RFEON pin, to be used as general on/off
switch on the RF module
■Control of the Z87001 sleep mode
4-Bit DAC for Setting Transmit Power Level
In order to save battery life, the Z87001 only transmits the
amount of RF power needed to reach the remote receiver
with a sufficient SNR margin. The on-board transmit power
4-bit DAC provides 4 different voltage levels to the power
amplifier in the RF module for that purpose. This DAC is di-
■Register initialization
■Implementation of high-level phone features; control of
phone user interface (keypad, Led, etc.)
■Control of the Z87010 ADPCM Processor
■Control of the phone line interface
■Ring detection by DSP processing
■Communication protocol between handset and base
station supporting voice and signalling channels
■Control of the RF synthesizer and adaptive frequency
hopping algorithm
■Control of the RF power and adaptive power algorithm
■Control of the demodulator (bit synchronizer loop filter,
AFC bias estimate filtering)
■Control of the modulator (carrier frequency) and
adaptive frequency alignment
■Signalling between base and handset to support above
The DSP core is characterized by an efficient hardware architecture that allows fast arithmetic operations such as
multiplication, addition, subtraction and multiply-accumulate of two 16-bit operands. Most instructions are executed
in one clock cycle.
The DSP core is operated at the internal speed of 8.192
MHz. It has an internal RAM memory of 512 16-bit words
divided in two banks. Six register pointers provide circular
buffering capabilities and dual operand fetching. Three
vectored interrupts are complemented by a six-level stack.
One interrupt is used by the transceiver, while the two remaining vectors are mapped into port P1. In the phone
system, one of these interrupts is customarily reserved for
the Z87010 ADPCM Processor. The other interrupt can be
used for custom purposes.
The Z87001 may access up to 64K 16 bit words of external
ROM including 4 words for interrupt and reset vectors. The
ROM is mapped at addresses 0000h to 3FFFh, as shown
in Figure 13.
3FFFh
3FFEh
3FFDh
3FFCh
3FFFh
Int. V ector 0
Int. V ector 1
Int. V ector 2
Reset Vector
■Control of battery charging and detection of low battery
conditions
■Implementation of additional features for customizing of
the phone
Z87010 Interface
In addition to providing clock signals to the Z87010 processor, the Z87001 interfaces to the Z87010 through two different paths:
■A command/status interface
■A data interface
The command/status interface consists of two dual-port
registers accessible by both Z87001 and Z87010 DSP
core processors. On the Z87001 side, the registers are
mapped into the DSP core processor’s register interface.
To allow access by the Z87010, the internal command/status registers can also be decoded on the pinto of the
Z87001. Arbitration logic resolves access contentions.
The data interface allows the Z87010 processor direct access to the Z87001’s receive and transmit rate buffers. The
rate buffers are decoded on the pin to of the Z87001, and
dedicated voice processor interface logic handles the addressing within the rate buffers.
64K
USER ROM
(EXTERNAL)
0000h
Figure 4. ROM Mapping
Two 16-Bit General-Purpose I/O Ports
Two 16-bit general-purpose I/O ports are directly accessible by the DSP core. These input and output pins are typically used for:
■Implementation of the phone’s user interface (keypad,
LED, optional display, etc.)
■Control of phone line interface (on/off hook, ring detect)
The physical interface between Z87001 and Z87010 consists of an 8-bit data bus, a 3-bit address bus and control
signals, as summarized in the following:
VXDATA[7.0]Data bus
VXADD[2.0]Address bus
VXSTRBData Strobe
VXRWBRead/Write Control
VXRDYBRead Control
This bus is controlled by the Z87010. Although in the system the Z87010 is enslaved to the Z87001 master, at the
physical level the Z87001 acts as a peripheral of the
Z87010.
The mapping of the command status and data interfaces
from the Z87010 side is given below.
The AFC loop consists of a bias estimator block, which determines frequency offsets in the incoming signal, an
adder, to add this bias to the 460 kHz frequency control
word driving the NCO, and various interface points to the
DSP core processor. In particular, the DSP can read the
bias estimate data and substitute its own calculated bias
value to the NCO.
The bias estimator accumulates the discriminator output
values (image of instantaneous frequency) that exceed a
programmable threshold (BIAS_THRESHOLD). The processor can freeze the bias calculation any time by resetting the BIAS_ENABLE control bit.
Rx signal
460 kHz
+ bias
Second downconvertor,
Discriminator
The accumulated bias, available in BIAS_ERROR_DATA,
can be used directly to correct the NCO frequency. Alternately, the estimated bias can be read by the DSP, further
processed, and written to the CORE_BIAS_DATA field.
The DSP controls which value is used by setting the
USE_CORE_BIAS field. The selected value is added to
the 460 kHz signal which downconverts the receive IF signal.
The CORE_BIAS_DATA and BIAS_ERROR_DATA are
two’s complement numbers in units of 125 Hz.
In addition to correcting the difference in clock frequencies
on the receiver using the AFC loop, a Z87001-base system
can also modify the frequency of the remote transmit IF
signals. The software has access to this frequency through
the MOD_FREQ register fields.
The MOD_FREQ fields specify the carrier center frequency (should be programmed to 2.508 MHz) and deviation for
the FSK signal (should be programmed to ± 32.58 kHz). In
addition, wave shaping is performed on bit transitions, in
order to satisfy FCC regulations. Up to four different intermediate deviation values are programmable for each of
the two FSK states. The MOD_FREQ fields are programmable in units of 62.5 Hz.
The bit synchronizer circuit is an implementation of the
Data-Transition-Tracking Loop (DTTL), best described in
“Telecommunications Systems Engineering”, by W. Lindsey and M. Simon (Dover 1973; oh. 9 p. 442). Its operation
is summarized in the following block diagram.
Signed
Error
Mid-phase
Matched
Filter
Recovered
Bit clock
Error
Magnitude
Clock
Generator
Loop Filter
division
first order
“by 1”
“by 64”
Figure 6. Bit Synchronizer Loop and Processor Control
The loop filter is controlled by the DSP core processor. The
DSP core can implement a first order loop by setting the
SECOND_ORDER field to zero. Typically, the
BSYNC_GAIN would then be set to “divide-by-1” operation
to provide a wide closed loop bandwidth and thus a quick
acquisition of the bit clock. When the bit clock is in phase
with the input data, the loop bandwidth can be narrowed to
maintain tracking of the receive clock with minimum impact
from signal noise. To reduce the loop bandwidth, the
BSYNC_GAIN can be set to “divide-by-64” the first order
gain, while the integrated tracking error (available to the
DSP in fields INT_SYM_ERR0 and INT_SYM_ERR1) can
be used by the DSP software to adjust the
SECOND_ORDER term.
The bit synchronizer relies on transitions in the received bit
stream to operate. The bit inversion logic guarantees
enough transitions for all transferred data.
At the handset, the bit synchronizer must track both frequency and phase of the receive signal’s data clock. At the
base, only the phase must be tracked. The frequency is inherently correct since the base is the source of the system’s data clock.
The handset only has one frame counter, which times all
receive and transmit events. The base station has distinct
transmit and receive frame counters. When used in this
document without any explicit reference to either base or
handset, the terms “receive frame counter” and “transmit
frame counter” refer to both sides. For the handset, both
terms refer to the same unique counter.
The frame counters are clocked at the bit rate, or 93.09
kHz (2.048 MHz/22). Each count lasts one bit =
1000/93.09 = 10.74 µs.
Each frame lasts 4 ms, which corresponds to (372 + 8/22)
bits; the frame counters count from 0 to 371, with the last
count lasting a bad longer than the other ones; at the end
of count 371, the counters wrap around to 0.
The “hop” command pulse is asserted to pin SYLE during
count “0” of the frame counter (transmit frame counter on
the base station).
Frame Synchronizer, Timings and
RF Interface
The frame synchronizer tracks the received frames and resets the receive frame counter. The synchronization is performed by recognizing certain data patterns present in the
receive bit stream: a comparison is done on the fly between the data pattern and the incoming bit stream; when
the data match, the frame counter is reset.
Two possible 16-bit data patterns are pre-programmed in
the Z87001. One is named UW (Unique Word) and is used
in acquisition mode for first-time synchronization to an incoming signal. UW can also be used to track an acquired
signal. The second pattern is named SYNC_D and is used
to track the received data frames while voice is being
transferred. The transition from tracking UW to tracking
SYNC_D is controlled by the DSP processor through the
SYNC_SEARCH_WORD field.
UW Synchronization
When the Z87001 matches the UW, the receive frame
counter is reset to the value of UW_LOCATION. This value
is programmable by the DSP processor. On the handset,
where the receive frame counter is used to derive all timings, UW_LOCATION actually defines the guard time between the frequency hop command and the beginning of
data reception, which starts at FRAME_COUNTER =
(UW_LOCATION - 84) as shown in the next figure.
On the base station, data reception starts when the receive
frame counter equals (UW_LOCATION - 84), but this has
less significance since the hop pulse is synchronized with
the transmit frame counter and there is no fixed relationship between transmit and receive frame counters. On the
base station, the UW_LOCATION should be set to 301.
Figure 7. Frame Counter and UW_LOCATION on Handset
Two modes of search are programmable through the
SYNC_SEARCH_MODE field: “full search” and “window
search”. The full search is used by the handset when first
acquiring the signal from the base station. In full search,
the handset is in receive mode and continuously looks for
a match with the UW. When a match is found and the time
reference established (UW_LOCATION is set), the DSP
processor on the handset detects the synchronization (see
below), switches to Time Division Duplex mode (TDD) and
starts receiving and transmitting alternately. The search
mode should also be switched to “window search” by the
DSP software.
The window search mode only searches for a match in a
certain time window centered around the expected match
time. The window size is programmable by the DSP processor in the WINDOW_SIZE field. If the matching does
not occur at the expected time, due to so-called “bit slips”,
the receive frame counter timing is adjusted. Note: although the bit synchronizer is meant to keep track of time
and prevent bit slips when the phone is operating continuously in TDD mode, bit slips are still possible when the
handset is in standby mode, and only receives once in a
while (see description of sleep mode).
SYNC_D Synchronization
When the DSP processor switches the Z87001 operation
to voice mode, the frame synchronization parameters
should be modified by the DSP software to:
■SYNC_SEARCH_MODE = window search
■SYNC_SEARCH_WORD = SYNC_D pattern
In this mode, the receiver searches for the SYNC_D pattern in windows of the incoming data stream. The window
size is determined by the WINDOW_SIZE field.
The transition to voice mode proceeds in two steps,
through an intermediate mode. The mode is set by the
DSP processor by programming the
MULTIPLEX_SWITCH field. The three modes are:
■SMUX: initial mode. This mode allows acquisition, AFC
operation, UW synchronization and signalling; ADPCM
Processor access disabled; bit inversion disabled.
■STMUX: intermediate mode. This mode allows
SYNC_D frame synchronization and signalling; ADPCM
Processor access disabled; bit inversion enabled.
■TMUX: voice mode. This mode allows voice
transmission, SYNC_D frame synchronization and
signalling; ADPCM Processor access enabled; bit
inversion enabled.
In order to detect synchronizations, the software has access to the SYNC_ACQ_IND status field. This field is set
by the Z87001 matching hardware every time a match is
detected within the right time window. The software must
reset the “IND” bit by setting the SYNC_ACQ_CLEAR
field.
In addition, the software can track the frame timing by
reading the frame counter value, available in the
FRAME_COUNTER field. On the base station, where two
frame counters are in use, this field returns the value of the
transmit frame counter.
Every time the frame counter wraps around to 0, a frame
start indicator bit is set (FRAME_START_IND status field).
The software must reset this “IND” bit by setting the
FRAME_START_CLEAR field. If the FS_INT_ENABLE bit
is set, frame starts also trigger interrupts to the DSP processor.
Several control fields are available in the Z87001 register
set to control the timing and polarity of the RF module interface signals.
A first field, RFEON_POLARITY, controls the polarity of
the RFEON pin. This pin should be used to control the
power of the RF module. It is asserted by the Z87001 when
the RF module is in use, and de-asserted in sleep mode.
The sleep mode is used by the handset to save battery life
when no phone call is in process (See “Sleep mode”, below).
The SYLE pin (Synthesizer Load Enable), which carries a
“load enable” pulse that tells an external RF synthesizer to
generate the next RF channel, is controlled by two fields.
The HOP_ENABLE field is a global enable signal for the
SYLE signals. The SYLE_POLARITY field defines the polarity of the SYLE pin. The system designer should ensure
that the leading edge of the SYLE pulse triggers channel
hopping.
In addition to the SYLE signal, the interface to the most RF
synthesizers includes two more input lines, “data” and
“clock”, for serial programming of the data values defining
the RF channel. In order to allow interfacing to various
popular synthesizers, the Z87001 does not have dedicated
clock and data lines with fixed timing. Instead, two general
I/O pins from ports P0 and P1 can be controlled in software
by the DSP core to realize any particular interface timing.
This flexibility is made possible by the high speed, singlecycle architecture of the DSP core.
The transmitter control includes a global enable signal for
all transmit functions: TX_ENABLE. The transmission start
is controlled by the MOD_PWR_ON field. On the base station, the value programmed in MOD_PWR_ON is referenced to the transmit frame counter.
Two additional fields, RFTX_PWR_ON and
RFTX_PWR_OFF, define the duty cycle of the PAON output pin. On the base station, these fields are referenced to
the transmit frame counter. The RFTX_POLARITY bit defines the polarity of the PAON pin. This pin can be used to
control the transmit section and power amplifier of the external RF module.
On the receive side, two fields define the internal timing of
the receiver. The start of reception is controlled by the
DEMOD_PWR_ON field. Stop of reception (and receiver
power down) is controlled by the DEMOD_PWR_OFF
field. On the base station, these fields are referenced to
the receive frame counter. The RXSW output pin follows
the timing defined by the DEMOD_PWR_ON and OFF
fields.
Two additional fields, RFRX_PWR_ON and
RFRX_PWR_OFF, define the duty cycle of the TXSW output pin. On the base station, these fields are referenced to
the TRANSMIT (!) frame counter. The RFRX_POLARITY
bit defines the polarity of the TXSW and RXSW pins. The
TXSW pin can be used to control the receive section of the
external RF module.
The various timing control registers reviewed in this paragraph should be programmed differently for handset and
base station. If the same ROM code is used on base and
handset, the software can determine which station it runs
on by reading the HAND_BASE_SEL bit, which reflects
the state of the HBSW pin.
To save the phone’s battery life on the handset, the
Z87001 can be operated in sleep mode while the phone is
not in use. The sleep mode is entered by software command. The sleep mode first needs to be enabled by setting
the SLEEP_WAKE field. Then a GO_TO_SLEEP command puts the processor to sleep by temporarily stopping
its clock. The sleep period can be set to last between 4 ms
and 1.02 s by programming the SLEEP_PERIOD field. In
sleep mode, the RFEON pin is de-asserted.
The processor comes out of sleep mode in one of two
ways. Either the sleep counter counts down to zero, or one
of the enabled pins from port P0 is asserted prior to normal
expiration of the counter. Four port pins (P0[0..4]) can be
individually enabled to provide the wake-up function by
setting the appropriate bits in P0_WAKE_ENABLE. Typically, these port pins are connected to the telephone keypad.
When the processor core wakes up, the software needs to
know how much time it was actually asleep, in order to restore synchronization to the base station’s hopping sequence. For that purpose, the current value of the sleep
counter is available to the processor in
SLEEP_REMAINING. A value of zero indicates normal expiration of the sleep counter.
In order to guarantee a good operation of the wake-up
pins, the wake-up signals are hardware-denounced by the
Z87001. Furthermore, these signals are internally synchronized to the bit clock. This ensures that the processor
has enough time (one bit time = 10.74 ms) to read a stable
value of the remaining sleep time and synchronize correctly to the base station’s hopping sequence.
The interface to the ADPCM Processor (Z87010) consists
of clock control, command/status interface and data interface. The data interface gives the ADPCM Processor access to the rate buffers.
Clock Interface
The Z87001 generates the Z87010 clock at 16.384 or
8.192 MHz, as set in VP_CLOCK. In addition, the clock
can be stopped and restarted with the VP_STOP_CLOCK
field in order to reduce power consumption (Note: a software handshaking between Z87001 and Z87010 is necessary before stopping and after restarting the clock).
In addition to providing the Z87010 main clock, the Z87001
generates a CODCLK signal which will be used by the codec and by the Z87010 to synchronize its data transfers
with the Z87001. On the base station, the CODCLK is simply obtained by dividing the 16.384 MHz input clock.
On the handset, the CODCLK is synchronized to the base
station’s CODCLK signal through the receive bit sync logic. This ensures that production and consumption of voice
data is happening at identical rates on handset and base,
eliminating buffer overrun and underrun situations.
Command/Status Interface
The Z87001 sends commands to the Z87010 through the
VP_COMMAND write-only field. It reads the Z87010 status in the VP_STATUS read-only field. Both fields are located at the same address in the Z87001 register interface. A communication protocol should be established in
software to ensure correct reception of all commands.
Dedicated hardware ensures data integrity when both
Z87001 and Z87010 simultaneously access the same register.
The digitized voice data is communicated between the
Z87001 and Z87010 through the rate buffers and ADPCM
Processor data interface. The transmit and receive rate
buffers each contain 36 4-bit nibbles.
To write to the transmit rate buffer, the Z87001 core processor must first set the nibble address in the
TX_BUF_ADDR register field, then write the nibble data
through TX_BUF_DATA. If the TX_AUTO_INCREMENT
bit is set, the address is automatically incriminated (modulo 51 = the number of nibbles in rate buffer + 15 additional
data words accessible through TX_BUF_DATA; for more
information, see Register Description) after each data
write. This allows the DSP core to write successive nibbles
without resetting the address each time.
The operation of the receive rate buffer is identical. The
Z87001 core processor must set the nibble address in
RX_BUF_ADDR, then read the nibble from
RX_BUF_DATA. If the RX_AUTO_INCREMENT bit is set,
the read address is automatically incriminated (modulo 36
= number of nibbles in rate buffer) after each data read.
This allows the DSP core to read successive nibbles without resetting the address each time.
Through its register interface, the Z87001 also controls
which rate buffer addresses the Z87010 ADPCM Processor can access. The nibble addresses are contained in the
RX RATE BUFFER
Demodulator
Address
Decoder
TX_BUF_VP_ADDR and RX_BUF_VP_ADDR register
fields. After the Z87010 writes or reads a nibble to or from
transmit or receive rate buffer, the corresponding
“VP_ADDR” is automatically incriminated (modulo 36) to
the next accessible address. The locations of accessible
addresses are individually controlled by the Z87001 in the
three TX_RX_NIBBLE_MARKER register fields. A marker
bit equal to “1” enables the Z87010 to access the corresponding address; a bit equal to “0” causes the Z87010’s
read or write access to skip to the next nibble that has a
marker bit equal to “1”.
Z87001
RX_BUF_VP_ADDR
TX_RX_NIBBLE_
MARKER
TX_BUF_VP_ADDR
Modulator
RX_BUF_DATA
TX RATE BUFFER
ADPCM Proc.
Interface
TX_BUF_DATA
RX_BUF_ADDR
RX_AUTO_INCR.
TX_BUF_ADDR
TX_AUTO_INCR.
DSP Core
Processor
VP_COMMAND
VP_STATUS
Figure 9. Rate Buffers Access and ADPCM Processor Interface
The Z87001 features several means of measuring and
controlling power levels. One input pin (RSSI) connects an
external “receive signal strength indicator” to a half flash 8bit ADC in the Z87001. This ADC is sampled once per
frame during the receive portion of the TDD cycle. The
RSSI value can be accessed in software in the
RSSI_DATA register field. With external multiplexing, the
8-bit ADC can be used for additional purposes.
The RSSI data is used by the software to implement adaptive power control. In order to determine whether the RSSI
information is made of signal or noise, the Z87001 includes
logic to measure the signal-to-noise ratio (SNR) of the receive signal. This SNR value is available at the end of every frame in the SNR_ESTIMATE register field. It is also
used by the adaptive frequency hopping algorithm to determine and avoid the noisy channels.
Finally, a 4-bit DAC (resistive ladder) is provided to control
RF power output level. The DAC is under software control
through register field TX_PWR_DAC_DATA.
Table 8. Power Control
General-Purpose I/O Ports
The Z87001 includes two general-purpose input/output
ports, P0 and P1, of 16 bit each. The direction of each bit
is independently programmable by setting the register
fields DIRECTION0 and DIRECTION1. Then, the software
can access the input and output values by accessing
DATA0 and DATA1.
Two pins of port P1 (pins 14 and 15), when configured in
input mode, also behave as interrupt pins for the core processor. The software can enable or disable each interrupt
by setting the INTERRUPT_0_ENABLE and
INTERRUPT_2_ENABLE fields. The interrupts are positive edge-triggered.
Four pins of port P0 (pins 0 to 3), when configured in input
mode, can also be individually programmed as wake-up
pins for the Z87001 (See “Sleep mode”, above).
The Z87001 DSP core processor has four banks of eight
registers mapped in the core processor’s “external register” space, as summarized in the following table.
Table 10. Register Summary
BANK ADDRESSREGISTERREAD DESCRIPTIONWRITE DESCRIPTIONTABLE #
Search control, Hop Enable, Frame Start control, Multiplex
control, Sleep mode control
EXT3SSPSTATUSFrame Counter, Handset/Base,
Sync Search control, Frame
Start control
EXT4GPIO0DIRGeneral-Purpose I/O port 0 direction controlTable 29
EXT5GPIO0DATAGeneral-Purpose I/O port 0 dataTable 30
EXT6GPIO1DIRGeneral-Purpose I/O port 1 direction controlTable 31
EXT7GPIO1DATAGeneral-Purpose I/O port 1 dataTable 32
Bank 2EXT0VP_INOUTADPCM Processor StatusADPCM Processor Command Table 33
The bank is selectable in software by writing to the core’s
status register (see Table 24). Once a bank is selected,
Table 11. Bank Switching
BankStatus RegisterBank Function
Bank 0xxxx xxxx x00x xxxx bTest point access, TDD switching control
Bank 1xxxx xxxx x01x xxxx bRate buffer access, miscellaneous
Bank 2xxxx xxxx x10x xxxx bADPCM processor interface, RF interface, etc.
Bank 3xxxx xxxx x11x xxxx bConfiguration, status, general-purpose port data and direction
each of the eight external registers (EXT0 through EXT7)
can be accessed by a single-cycle software instruction.
Bank 3 Registers
Table 12. Bank 3 Registers
Config 1
Field
RESERVEDf---------------R
VP_CLOCK-e--------------
USE_CORE_BIAS --d-------------
SYLE_POLARITY ---c------------
WINDOW_SIZE----ba98--------
BIAS_THRESHOLD-------76543210
Notes:
1. VP_CLOCK. Internally synchronized to avoid glitches. Changes to this bit take effect immediately.
2. SYLE_POLARITY. Changes to this bit take effect immediately.
3. BIAS_THRESHOLD. The bias threshold must be coded as a negative value
(opposite of the threshold value) coded in 2’s complement. The nominal value for the
threshold is -46 (=D3h). Internally, this value is sign-extended to 13 bits.
Bank 3
Bit Position
EXT0
R/WData Description
Returns 0
W
R
W0*
R
W0
R
W0000
0001
•••
1111
R
WXXh
Must be set to 1
Controls CLKOUT output pin (clock for ADPCM Processor).
Returns 0
0
CLOCKOUT=16.384 MHz
1
CLOCKOUT = 8.192
Controls which bias value is used by the downconverter’s
NCO as part of the automatic frequency control loop (AFC)
Returns 0
Uses BIAS_ERROR_DATA value from AFC hardware
1
Uses CORE_BIAS_DATA value from DSP core
Controls the polarity of the SYLE output pin (hop pulse)
Returns 0
SYLE is a positive pulse
1
SYLE is a negative pulse
Defines the search window size (in bits) for windo wed search
mode (for Unique Word or SYNC_D words).
Returns 0
Window size=1
Window size =3 (1±1)
Window size = 31 (1± 15)
Bias estimator threshold value
1. SLEEP_PERIOD. In sleep mode, the RFEON pin is active. Changes to this bit take effect immediately.
2. SLEEP_REMAINING. A non-zero value indicates that the Z87001 was awakened by a key press activating one of the wake-up
pins on port 0. In this case, the processor should immediately reset the SLEEP_WAKE field in SSPSTATE to prevent the process from going back to sleep when the user key press ceases.
Bank 3
Bit Position
EXT1
R/WDataDescription
Controls optional antenna switching
(ANT0 and ANT1 pins)
R
W0
R
WxXh
R00h
Returns 0
Enables antenna switching
1
Disables antenna switching
Controls antenna switching time advancement
Returns 0
Offset in number of 2.048 MHz clock cycles
(<108)
Programs sleep duration in sleep mode Illegal
01h
Sleep period=1 frame (4 ms)
•••
FFh
Sleep period = 255 frames (1.020s)
Returns value of sleep counter when sleep mode
is interrupted by a “wake” signal
Normal expiration of sleep counter
1. DBP_STOP_CLOCK. When this bit is set to 1, the ADPCM Processor clock (CLKOUT) is stopped within two clock periods. When
this bit is set to 0, the ADPCM Processor clock restarts within two clock periods; in every case, the ADPCM Processor clock minimum specifications for high time and low time are respected.
2. BSYNC_GAIN. Changes to this bit take effect immediately.
BIAS_ENABLE. This bit is a global enable for the Automatic Frequency Control. When the bit is set, the AFC hardware updates
the current BIAS_ERROR_DATA during specific time windows, controlled by the event trigger hardware and suitable for a good
operation of the AFC. When the bit is reset, the AFC operation is suspended. However, the current BIAS_ERROR_DATA, resulting from previous bias estimations, can still be used to bias the downconverter NCO. Changes to the BIAS_ENABLE bit take effect
at the beginning of the frame following the change.
3. TX_ENABLE. Global control for all system transmit functions, including PAON pin control (timing set by the RFTX_PWR_ON/OFF
register fields) and power to the modulator and NCO (timing set by MOD_PWR_ON and the wake/sleep modes).
4. Changes to this bit take effect immediately.
5. HOP_ENABLE. Changes to this bit take effect immediately.
6. SLEEP_WAKE. This bit must be set to enable the core to put itself to sleep via the GO_TO_SLEEP command. The SLEEP_WAKE
bit must be reset to prevent the core to fall back to sleep after it is awaken by one of the Port 0 Wake-up pins when the sleep period
has not expired. If the bit is not reset, the core will fall right back to sleep when the wake-up input is de-asserted (note that by
design, a wake-up input has a minimum of 10 ms duration, to allow the software enough time to safely reset the SLEEP_WAKE
bit).
7. SYNC_AQC_CLEAR. This bit must be set to “1” again after every “clear” operation to allow for the next “clear”.
8. FRAME_START_CLEAR. This bit must be set to “1” again after every “clear” operation to allow for the next ?“clear”.
Bank 3
Bit Position
EXT2
R/W DataDescription
Command bit to place the Z87001 in sleep mode
R
W0->1
R/W 0*
1
R/W 0*
1
R/W 00*
01
10
11
R/W 0
1
R
W1->0
R
W1->0
R/W 0
1
R/W 00*
01
10
11
R
W0->1
Returns last value written
A transition from 0 to 1 causes Z87001 sleep mode
Global enable for all transmit functions
Transmitter disabled
Transmitter enabled
Controls the word searched for in search mode
Search for UW pattern (Unique Word)
Search for SYNC_D pattern
Controls the search mode (and frame synchronization)
No search
Window search (<= UW_LOCATION & WINDOW_SIZE)
Full search (during whole frame)
Not used
Enables transmission of the hop pulse on SYLE pin
Hop pulse disabled
Hop pulse enabled
Clears the SYNC_ACQ_IND flag.
Returns last value written
A transition from 1 to 0 clears the flag
Clears the FRAME_START_IND flag
Returns last value written
A transition from 1 to 0 clears the flag
Enable bit for entering sleep mode
Wake mode only
Sleep mode can be activated by GO_TO_SLEEP command
Controls operation of the transceiver
SMUX (bit inversion and ADPCM Processor access disabled)
STMUX (bit inv. enabled; ADPCM Proc. access disabled)
Reserved
TMUX (bit inversion and ADPCM Processor access enabled)
RSSI_DATA. This value is sampled once per frame (4ms) approximately at bit 72 (middle) of the received data.
CORE_BIAS
Field
RESERVEDfed-------------R
CORE_BIAS_DATA---cba9876543210
Notes:
CORE_BIAS_DATA.This value is used if the USE_CORE_BIAS register field is set. It is encoded as a 2’s complement number.
The unit is 125 Hz.
Bank 2
Bit Position
Bank 2
Bit Position
EXT3
R/WDataDescription
Returns 0
W
R
W
Table 24. Bank 2 Register Description
EXT4
R/WDataDescription
W
R
WxXXXh
No effect
Access to 8-bit ADC (can be used for RSSI data)
XXh
Returns latest value on 8-bit DAC
No effect
Returns 0
No effect
Stores bias value for correction of downconverter’s
NCO.
Returns 0
Updates bias value
Table 25. Bank 2 Register Description
MOD_PWR_CTRL
Field
RESERVEDf---------------R
MOD_PWR_ON-edcba98--------
RESERVED--------76543210R
Notes:
1. MOD_PWR_ON. Controls the turn-on time for the internal modulator and NCO. Only the 7 LSBits of the 9-bit value necessary
to encode an event (from frame counter 0 to 371) are programmable. The two MSBits have fixed values which depend on
whether base station or handset is selected: “00” on the base and “01” on the handset. The modulator’s turn-off time occurs
a fixed time (number of bits) after the turn-on time: 144 bits on the base station, 148 bits on the handset.
2. Changes to this value take effect immediately.
3. To disable the modulator continuously, clear TX_ENABLE
Bank 2
Bit Position
EXT5
R/WDataDescription
Returns 0
W
R
WxXh
W
No effect
Determines modulator turn-on time referenced to the
transmit frame counter
Returns 0
Bits 6-0 of turn-on time (=(x modulo 128) -1)
Active Low
Determines internal power up of demodulator and turn
on time of RXSW pin, referenced to the receive frame
counter
R
WxXh
RESERVED--------7-------R
W
DEMOD_PWR_OFF---------6543210
Returns 0
Bits 6-0 of turn-on time (=(x modulo 128) -1)
Returns 0
No effect
Determine internal power down of demodulator and
turn off time of RXSW pin, referenced to the receive
frame counter
R
WXXh
Notes:
1. DEMOD_PWR_ON, DEMOD_PWR_OFF. Controls internal receive hardware and the RXSW output pin. The turn-on and off times
are given in number of received bit periods and are referenced to the Receive Frame Counter. Only the 7 LSBits of the 9-bit value
are programmable. The two MSBits have fixed values which depend on whether base station or handset is selected. For
DEMOD_PWR_ON, the two bits are “01” on the base and “00” on the handset. For DEMOD_PWR_OFF, the two bits are “10” on
the base and “01” on the handset
2. Changes to these values take effect immediately.
3. To enable receive power continuously, clear TX_ENABLE and set SYNC_SEARCH_MODE to FULL_SEARCH (this is the case
in acquisition mode).
4. The polarity of the RXSW output pin is controlled by the RFRX_POLARITY bit in the RFRX_PWR_CTRL register
Returns 0
Bits 6-0 of turn-off time (=(x modulo 128) -1)
1. RFTX_PWR_ON, RFTX_PWR_OFF. Controls the PAON output pin, and thereby the external RF module’s transmitter.
The turn-on and off times are given in number of transmitted bit periods and are referenced to the transmit Frame Counter.
Only the 7 LSBits of the 9-bit value are programmable. The two MSBits have fixed values which depend on whether base
station or handset is selected. For RFTX_PWR_ON, the two bits are “00” on the base and “01” on the handset. For
RFTX_PWR_OFF, the two bits are “01” on the base and “10” on the handset.
2. Changes to these values take effect immediately.
3. To disable the transmitter continuously, clear TX_ENABLE in SSP_STATE.
Bank 2
Bit Position
EXT7
R/WDataDescription
Controls the polarity of the PAON output pin
R
W0
R
WxXh
W
R
WxXh
Returns 0
Active high
1
Active Low
Determines PAON output pin turn-on time
referenced to the transmit frame counter
Returns 0
Bits 6-0 of turn-on time (=(x modulo 128) -1)
Returns 0
No effect
Determine PAON output pin turn-off time
referenced to the transmit frame counter
Returns 0
Bits 6-0 of turn-off time (=(x modulo 128) -1)
Reads value at current RX_BUF_ADDR
address (0 to 23h)
TX_BUF_DATA------------3210
WXXXXh
Access to the Tx rate buffer data
Writes value at current TX_B UF_ADDR address
(0 to 23h)
TX_BUF_VP_ADDR--dcba98--------
Sets the initialization value of the Tx rate buffer
address used for ADPCM Processor accesses
WXXh
Writes initialization value (TX_BUF_ADDR
address= 24h)
RX_BUF_VP_ADDR----------543210
Sets the initialization value of the Rx rate buffer
address used for ADPCM Processor accesses
WXXh
Writes initialization value (TX_BUF_ADDR
address= 24h)
TX_RX_NIBBLE_MARKER fedcba9876543210
Sets the Nibble Marker register for Tx and Rx
rate buffer accesses by ADPCM Processor
WXXXXh
Write nibble marker value (TX_BUF_ADDR=
25h to 27h)
MOD_FREQfedcba9876543210
WXXXXh
Access to modulator settings
Writes modulator setting value
(TX_BUF_ADDR=28h to 32h)
Note:
The meaning and address for any RATE_BUF_DATA is set in the RATE_BUF_ADDR register.
MOD_FREQ. The unit for center frequency and frequency deviation words is 62.5 Hz.
These words are encoded as 2’s complement numbers.
The meaning and address for any RATE_BUF_DATA is set in the RATE_BUF_ADDR register.
MOD_FREQ. The unit for center frequency and frequency deviation words is 62.5 Hz.
These words are encoded as 2’s complement numbers.
Table 30. Bank 1 Register Description
BIT_SYNC
Field
INT_SYM_ERR1fedcba9876543210
Bank 1
Bit Position
EXT2
R/WDataDescription
Read access to the integrated symbol error from the bit
synchronizer’s second order loop
RXXXXh
Reads error data bits [23..8] (bits [7..0] are in bank 0,
EXT6)
SECOND_ORDERfedcba9876543210
WXXXXh
Write access to the bit synchronizer’s second-order loop
Writes second order loop’s 16-bit value
Must be left alone or written to 0000h (or
unpredictable results may occur)
Table 32. Bank 1 Register Description
CONTROL
Field
RESERVEDfedcb-----------R
FS_INT_ENABLE-----a----------
INTERRUPT_0_ENABLE ------9---------
INTERRUPT_2_ENABLE -------8--------
P0_WAKEUP_ENABLE--------7654----
TX_PWR_DAC_DATA------------3210
Note:
P0_WAKEUP_ENABLE. When enabled, pins P0[3..0] are active low wake-up pins for the Z87001 sleep mode.
The input signal is internally debounced and synchronized to the bit clock. It is internally given a minimum duration of one bit to
allow the software to exit sleep mode safely.
Bank 1
Bit Position
EXT6
R/WDataDescription
Returns 0
W
No effect
Controls frame start interrupt (INT1)
R/W0*
Disables frame start interrupt
1
Enables frame start interrupt
Controls interrupt 0 (INT0 on P114)
R/W0*
Disables interrupt 0
1
Enables interrupt 0
Controls interrupt 2 (INT2 on P115)
Controls the polarity of the TXSW (and RXSW)
output pins
R
W0
RFRX_PWR_ON-edcba98--------
Returns 0
TXSW active Low and RXSW active High
1
TXSW active High and RXSW active Low
Determines TXSW output pin turn-on time
referenced to the transmit frame counter
R
WxXh
RESERVED--------7-------R
W
RFRX_PWR_OFF---------6543210
Returns 0
Bits 6-0 of turn-on time (=(x modulo 128) -1)
Returns 0
No effect
Determine TXSW output pin turn-off time
referenced to the transmit frame counter
R
WxXh
Notes:
1. RFRX_POLARITY. Caution: notice the inverse polarity of the TXSW pin.
2. RFRX_PWR_ON, RFRX_PWR_OFF. Controls the TXSW output pin. The turn-on and off times are given in number of transmitted bit periods and are referenced to the TRANSMIT (!) Frame Counter. Only the 7 LSBits of the 9-bit value are programmable. The two MSBits have fixed values which depend on whether base station or handset is selected. For
RFRX_PWR_ON, the two bits are “00” on the base and “01” on the handset. For RFRX_PWR_OFF, the two bits are “01”
on the base and “10” on the handset.
3. Changes to these values take effect immediately.
4. To disable transmit power continuously, clear TX_ENABLE.
Returns 0
Bits 6-0 of turn-off time (=(x modulo 128) -1)