TDMA T2290/T2297:
Memory
B38
Description
A serial EEP ROM(U1908) of 256K bytes is used for storage of the NAM information, authentication keys, phasing dat a, ESN, and memory. The EEPROM serial inter -
face to the microcontroller i s a standard SPI-compatible i nterface.
U1300 is a 64K x 16 low voltage, low power SRAM. U1300 uses a parallel interface bus.
U1200 is a 512K x 16 flash EPROM. U1200 uses a parallel interface bus.
The WP* line is used during EPROM flash con ditions. When the EPROM is not being flash ed, WP* is at a low state. This condition w ill switch Q1811 off, thus, allowing
the gate of Q1806 to be pulled high. A high state at th e gate of Q1806 will switch Q1806 off, thus, not allow ing WP* from U1200 to be pulled high by B+.
During flashing condi tions, WP* is pulled high. This condition will switch Q1811 on , allowing the voltage at the gate of Q1806 to drop. A lower voltage at the gate of
Q1806 will switch the transistor on. This condition will allow WP* from U1200 to be pulled high by B+.
B+
WP*
Q1806
Q1811
U1200
WP*
R1201
Содержание T2290
Страница 1: ...DIGITAL WIRELESS TELEPHONE Service Manual Level 3 Release 1 TDMA T2290 T2297 ...
Страница 26: ... 2000 Motorola Inc TDMA T2290 T2297 Cellular Overview 16 ...
Страница 40: ...Motorola Confidential Proprietary TDMA T2290 T2297 TDMA Test Mode NAM Programming 30 ...
Страница 68: ...Disassembly TDMA T2290 T2297 Keypad Removal Motorola Confidential Proprietary 58 ...