MRF24J40_08 Datasheet, PDF (133/152 Pages) Microchip Technology – IEEE 802.15.4™ 2.4 GHz RF Transceiver

FIGURE 4-4:
EXTERNAL PA/LNA TIMING DIAGRAM
Receive
Time
Transmit
Beginning of
Transmit
MRF24J40
Beginning of
Packet
GPIO0
GPIO1
GPIO2
t_RFSTBL
144 µs
t_TXON
98 µs
t_PAON
18 µs
RF Stabilization Time (t_RFSTBL) = RFSTBL * 16 µs
144 µs = 9 * 16 µs
Transmit On Time (t_TXON) = TXONTS * 16 µs + TXONT * 50 ns
98 µs = 6 * 16 µs + 40 * 50 ns
PA On Time (t_PAON) = PAONTS * 16 µs + PAONT + 50 ns
18.05 µs = 1 * 16 µs + 41 * 50 ns
Rule: t_rfstbl > t_txon > t_paon
TABLE 4-2: REGISTERS ASSOCIATED WITH EXTERNAL PA/LNA
Addr. Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
0x15 SYMTICKH TXONT6 TXONT6 TXONT6 TXONT6 TXONT6 TXONT6
TXONT6
TICKP8
0x16 PACON0 PAONT7 PAONT6 PAONT5 PAONT4 PAONT3 PAONT2
PAONT1
PAONT0
0x17 PACON1
r
r
r
PAONTS3 PAONTS2 PAONTS1 PAONTS0 PAONT8
0x18 PACON2 FIFOEN
r
TXONTS3 TXONTS2 TXONTS1 TXONTS0 TXONT8
TXONT7
0x2E TXSTBL RFSTBL3 RFSTBL2 RFSTBL1 RFSTBL0 MSIFS3
MSIFS2
MSIFS1
MSIFS0
0x22F TESTMODE
r
r
r
RSSIWAIT1 RSSIWAIT0 TESTMODE2 TESTMODE1 TESTMODE0
© 2008 Microchip Technology Inc.
Preliminary
DS39776B-page 131